Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Review Article
  • Published:

The assembly, regulation and function of the mitochondrial respiratory chain

Nature Reviews Molecular Cell Biology volume 23, pages 141–161 (2022)Cite this article

Subjects

Abstract

The mitochondrial oxidative phosphorylation system is central to cellular metabolism. It comprises five enzymatic complexes and two mobile electron carriers that work in a mitochondrial respiratory chain. By coupling the oxidation of reducing equivalents coming into mitochondria to the generation and subsequent dissipation of a proton gradient across the inner mitochondrial membrane, this electron transport chain drives the production of ATP, which is then used as a primary energy carrier in virtually all cellular processes. Minimal perturbations of the respiratory chain activity are linked to diseases; therefore, it is necessary to understand how these complexes are assembled and regulated and how they function. In this Review, we outline the latest assembly models for each individual complex, and we also highlight the recent discoveries indicating that the formation of larger assemblies, known as respiratory supercomplexes, originates from the association of the intermediates of individual complexes. We then discuss how recent cryo-electron microscopy structures have been key to answering open questions on the function of the electron transport chain in mitochondrial respiration and how supercomplexes and other factors, including metabolites, can regulate the activity of the single complexes. When relevant, we discuss how these mechanisms contribute to physiology and outline their deregulation in human diseases.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Overview of the structure and function of the mitochondrial oxidative phosphorylation machinery.
Fig. 2: Structural properties of the electron transport chain.
Fig. 3: Assembly process of respiratory complexes and supercomplexes.
Fig. 4: Regulation of the electron transport chain by supercomplexes.

Similar content being viewed by others

References

  1. Nicholls, D. Bioenergetics - 4th Edition (Academic Press, 2013).

  2. Green, D. E. & Tzagoloff, A. The mitochondrial electron transfer chain. Arch. Biochem. Biophys. 116, 293–304 (1966).

    CAS  PubMed  Google Scholar 

  3. Krebs, H. A. & Johnson, W. A. The role of citric acid in intermediate metabolism in animal tissues. Enzymologia 4, 148–156 (1937).

    CAS  Google Scholar 

  4. Jones, A. J. Y., Blaza, J. N., Varghese, F. & Hirst, J. Respiratory complex I in Bos taurus and Paracoccus denitrificans pumps four protons across the membrane for every NADH oxidized. J. Biol. Chem. 292, 4987–4995 (2017).

    CAS  PubMed  PubMed Central  Google Scholar 

  5. Mitchell, P. Possible molecular mechanisms of the protonmotive function of cytochrome systems. J. Theor. Biol. 62, 327–367 (1976).

    CAS  PubMed  Google Scholar 

  6. Trumpower, B. L. The protonmotive Q cycle. Energy transduction by coupling of proton translocation to electron transfer by the cytochrome bc1 complex. J. Biol. Chem. 265, 11409–11412 (1990).

    CAS  PubMed  Google Scholar 

  7. Maréchal, A. et al. A common coupling mechanism for A-type heme-copper oxidases from bacteria to mitochondria. Proc. Natl Acad. Sci. USA 117, 9349–9355 (2020).

    PubMed  PubMed Central  Google Scholar 

  8. Rizwan, M., Rasheed, H. Al, & Tarjan, G. Succinate dehydrogenase complex: an updated review. Arch. Pathol. Lab. Med. 142, 1564–1570 (2018).

    Google Scholar 

  9. Wang, Y. & Hekimi, S. Understanding ubiquinone. Trends Cell Biol. 26, 367–378 (2016).

    CAS  PubMed  Google Scholar 

  10. Alcázar-Fabra, M., Rodríguez-Sánchez, F., Trevisson, E. & Brea-Calvo, G. Primary coenzyme Q deficiencies: a literature review and online platform of clinical features to uncover genotype-phenotype correlations. Free Radic. Biol. Med. 167, 141–180 (2021).

    PubMed  Google Scholar 

  11. Mitchell, P. Coupling of phosphorylation to electron and hydrogen transfer by a chemi-osmotic type of mechanism. Nature 191, 144–148 (1961).

    CAS  PubMed  Google Scholar 

  12. Tang, J. X., Thompson, K., Taylor, R. W. & Oláhová, M. Mitochondrial OXPHOS biogenesis: co-regulation of protein synthesis, import, and assembly pathways. Int. J. Mol. Sci. 21, 1–32 (2020).

    Google Scholar 

  13. Cogliati, S., Lorenzi, I., Rigoni, G., Caicci, F. & Soriano, M. E. Regulation of mitochondrial electron transport chain assembly. J. Mol. Biol. 430, 4849–4873 (2018).

    CAS  PubMed  Google Scholar 

  14. Priesnitz, C. & Becker, T. Pathways to balance mitochondrial translation and protein import. Genes. Dev. 32, 1285–1296 (2018).

    CAS  PubMed  PubMed Central  Google Scholar 

  15. Cardenas-Rodriguez, M., Chatzi, A. & Tokatlidis, K. Iron–sulfur clusters: from metals through mitochondria biogenesis to disease. J. Biol. Inorg. Chem. 23, 509–520 (2018).

    CAS  PubMed  PubMed Central  Google Scholar 

  16. Swenson, S. A. et al. From synthesis to utilization: the ins and outs of mitochondrial heme. Cells 9, 579 (2020).

    CAS  PubMed Central  Google Scholar 

  17. Pierron, D. et al. Cytochrome c oxidase: evolution of control via nuclear subunit addition. Biochim. Biophys. Acta 1817, 590–597 (2012).

    CAS  PubMed  Google Scholar 

  18. Xia, D. et al. Structural analysis of cytochrome bc1 complexes: implications to the mechanism of function. Biochim. Biophys. Acta 1827, 1278–1294 (2013).

    CAS  PubMed  Google Scholar 

  19. Stroud, D. A. et al. Accessory subunits are integral for assembly and function of human mitochondrial complex I. Nature 538, 123–126 (2016).

    CAS  PubMed  Google Scholar 

  20. Ghezzi, D. & Zeviani, M. Assembly factors of human mitochondrial respiratory chain complexes: physiology and pathophysiology. Adv. Exp. Med. Biol. 748, 65–106 (2012).

    CAS  PubMed  Google Scholar 

  21. Páleníková, P. et al. Duplexing complexome profiling with SILAC to study human respiratory chain assembly defects. Biochim.Biophys. Acta Bioenerg. 1862, 148395 (2021).

    PubMed  Google Scholar 

  22. Maldonado, M., Guo, F. & Letts, J. A. Atomic structures of respiratory complex III2, complex IV, and supercomplex III2-IV from vascular plants. eLife 10, 1–34 (2021).

    Google Scholar 

  23. Letts, J. A., Fiedorczuk, K., Degliesposti, G., Skehel, M. & Sazanov, L. A. Structures of respiratory supercomplex I+III2 reveal functional and conformational crosstalk. Mol. Cell 75, 1131–1146.e6 (2019).

    CAS  PubMed  PubMed Central  Google Scholar 

  24. Letts, J. A., Fiedorczuk, K. & Sazanov, L. A. The architecture of respiratory supercomplexes. Nature 537, 644–648 (2016).

    CAS  PubMed  Google Scholar 

  25. Wu, M., Gu, J., Guo, R., Huang, Y. & Yang, M. Structure of mammalian respiratory supercomplex I1III2IV1. Cell 167, 1598–1609.e10 (2016).

    CAS  PubMed  Google Scholar 

  26. Guo, R., Zong, S., Wu, M., Gu, J. & Yang, M. Architecture of human mitochondrial respiratory megacomplex I2III2IV2. Cell 170, 1247–1257 (2017).

    CAS  PubMed  Google Scholar 

  27. Gu, J. et al. The architecture of the mammalian respirasome. Nature 537, 639–643 (2016). This, along with Letts et al. (2016), reported the first structure of the mammalian respirasome.

    CAS  PubMed  Google Scholar 

  28. Rathore, S. et al. Cryo-EM structure of the yeast respiratory supercomplex. Nat. Struct. Mol. Biol. 26, 50–57 (2019).

    CAS  PubMed  Google Scholar 

  29. Hartley, A. M. et al. Structure of yeast cytochrome c oxidase in a supercomplex with cytochrome bc1. Nat. Struct. Mol. Biol. 26, 78–83 (2019). This, along with Rathore et al., reported the first structure of the mitochondrial yeast supercomplex CIII2CIV.

    CAS  PubMed  Google Scholar 

  30. Hartley, A. M., Meunier, B., Pinotsis, N. & Maréchal, A. Rcf2 revealed in cryo-EM structures of hypoxic isoforms of mature mitochondrial III-IV supercomplexes. Proc. Natl Acad. Sci. USA 117, 9329–9337 (2020).

    CAS  PubMed  PubMed Central  Google Scholar 

  31. Schägger, H. & Pfeiffer, K. Supercomplexes in the respiratory chains of yeast and mammalian mitochondria. EMBO J. 19, 1777–1783 (2000). First characterization of supercomplexes.

    PubMed  PubMed Central  Google Scholar 

  32. Moe, A. et al. Cryo-EM structure and kinetics reveal electron transfer by 2D diffusion of cytochrome c in the yeast III-IV respiratory supercomplex. Proc. Natl Acad. Sci. USA 118, e2021157118 (2021).

    CAS  PubMed  PubMed Central  Google Scholar 

  33. Lobo-Jarne, T. et al. Multiple pathways coordinate assembly of human mitochondrial complex IV and stabilization of respiratory supercomplexes. EMBO J. 39, e103912 (2020).

    CAS  PubMed  PubMed Central  Google Scholar 

  34. Protasoni, M. et al. Respiratory supercomplexes act as a platform for complex III-mediated maturation of human mitochondrial complexes I and IV. EMBO J. 39, e102817 (2020).

    CAS  PubMed  PubMed Central  Google Scholar 

  35. Fernandez-Vizarra, E. & Zeviani, M. Mitochondrial disorders of the OXPHOS system. FEBS Lett. 595, 1062–1106 (2020).

    PubMed  Google Scholar 

  36. Bratic, A. & Larsson, N. G. The role of mitochondria in aging. J. Clin. Invest. 123, 951–957 (2013).

    CAS  PubMed  PubMed Central  Google Scholar 

  37. Mukherjee, S. & Ghosh, A. Molecular mechanism of mitochondrial respiratory chain assembly and its relation to mitochondrial diseases. Mitochondrion 53, 1–20 (2020).

    CAS  PubMed  Google Scholar 

  38. Signes, A. & Fernandez-Vizarra, E. Assembly of mammalian oxidative phosphorylation complexes I–V and supercomplexes. Essays Biochem. 62, 255–270 (2018).

    PubMed  PubMed Central  Google Scholar 

  39. Grba, D. N. & Hirst, J. Mitochondrial complex I structure reveals ordered water molecules for catalysis and proton translocation. Nat. Struct. Mol. Biol. 27, 892–900 (2020).

    CAS  PubMed  PubMed Central  Google Scholar 

  40. Kampjut, D. & Sazanov, L. A. The coupling mechanism of mammalian respiratory complex I. Science 370, eabc4209 (2020). Structure-based description of the coupling mechanism of mammalian complex I.

    CAS  PubMed  Google Scholar 

  41. Gutiérrez-Fernández, J. et al. Key role of quinone in the mechanism of respiratory complex I. Nat. Commun. 11, 4135 (2020).

    PubMed  PubMed Central  Google Scholar 

  42. Zhou, L. & Sazanov, L. A. Structure and conformational plasticity of the intact Thermus thermophilus V/A-type ATPase. Science 365, eaaw9144 (2019).

    CAS  PubMed  Google Scholar 

  43. Pinke, G., Zhou, L. & Sazanov, L. A. Cryo-EM structure of the entire mammalian F-type ATP synthase. Nat. Struct. Mol. Biol. 27, 1077–1085 (2020).

    CAS  PubMed  Google Scholar 

  44. Spikes, T. E., Montgomery, M. G. & Walker, J. E. Structure of the dimeric ATP synthase from bovine mitochondria. Proc. Natl Acad. Sci. USA 117, 23519–23526 (2020).

    CAS  PubMed  PubMed Central  Google Scholar 

  45. Fiedorczuk, K. et al. Atomic structure of the entire mammalian mitochondrial complex I. Nature 538, 406–410 (2016).

    CAS  PubMed  PubMed Central  Google Scholar 

  46. Zhu, J., Vinothkumar, K. R. & Hirst, J. Structure of mammalian respiratory complex I. Nature 536, 354–358 (2016).

    CAS  PubMed  PubMed Central  Google Scholar 

  47. Chomyn, A. et al. Six unidentified reading frames of human mitochondrial DNA encode components of the respiratory-chain NADH dehydrogenase. Nature 314, 592–597 (1985).

    CAS  PubMed  Google Scholar 

  48. Chomyn, A. et al. URF6, last unidentified reading frame of human mtDNA, codes for an NADH dehydrogenase subunit. Science 234, 614–618 (1986).

    CAS  PubMed  Google Scholar 

  49. Baradaran, R., Berrisford, J. M., Minhas, G. S. & Sazanov, L. A. Crystal structure of the entire respiratory complex I. Nature 494, 443–448 (2013).

    CAS  PubMed  PubMed Central  Google Scholar 

  50. Formosa, L. E. et al. Dissecting the roles of mitochondrial complex I intermediate assembly complex factors in the biogenesis of complex I. Cell Rep. 31, 107541 (2020).

    CAS  PubMed  Google Scholar 

  51. Guerrero-Castillo, S. et al. The assembly pathway of mitochondrial respiratory chain complex I. Cell Metab. 25, 128–139 (2017).

    CAS  PubMed  Google Scholar 

  52. Formosa, L. E. et al. Optic atrophy–associated TMEM126A is an assembly factor for the ND4-module of mitochondrial complex I. Proc. Natl Acad. Sci. USA 118, e2019665118 (2021).

    CAS  PubMed  PubMed Central  Google Scholar 

  53. Sánchez-Caballero, L. et al. TMEM70 functions in the assembly of complexes I and V. Biochim. Biophys. Acta Bioenerg. 1861, 148202 (2020).

    PubMed  Google Scholar 

  54. Carroll, J., He, J., Ding, S., Fearnley, I. M. & Walker, J. E. TMEM70 and TMEM242 help to assemble the rotor ring of human ATP synthase and interact with assembly factors for complex I. Proc. Natl Acad. Sci. USA 118, e2100558118 (2021).

    CAS  PubMed  PubMed Central  Google Scholar 

  55. Pierrel, F. et al. Coa1 links the Mss51 post-translational function to Cox1 cofactor insertion in cytochrome c oxidase assembly. EMBO J. 26, 4335–4346 (2007).

    CAS  PubMed  PubMed Central  Google Scholar 

  56. Leif, H., Sled, V. D., Ohnishi, T., Weiss, H. & Friedrich, T. Isolation and characterization of the proton-translocating NADH:ubiquinone oxidoreductase from Escherichia coli. Eur. J. Biochem. 230, 538–548 (1995).

    CAS  PubMed  Google Scholar 

  57. Sazanov, L. A. & Hinchliffe, P. Structure of the hydrophilic domain of respiratory complex I from Thermus thermophilus. Science 311, 1430–1436 (2006).

    CAS  PubMed  Google Scholar 

  58. Verkhovskaya, M. L., Belevich, N., Euro, L., Wikström, M. & Verkhovsky, M. I. Real-time electron transfer in respiratory complex I. Proc. Natl Acad. Sci. USA 105, 3763–3767 (2008).

    CAS  PubMed  PubMed Central  Google Scholar 

  59. Berrisford, J. M. & Sazanov, L. A. Structural basis for the mechanism of respiratory complex I. J. Biol. Chem. 284, 29773–29783 (2009).

    CAS  PubMed  PubMed Central  Google Scholar 

  60. Parey, K. et al. Cryo-EM structure of respiratory complex I at work. eLife 7, e39213 (2018).

    PubMed  PubMed Central  Google Scholar 

  61. Bridges, H. R. et al. Structure of inhibitor-bound mammalian complex I. Nat. Commun. 11, 1–11 (2020).

    Google Scholar 

  62. Verkhovskaya, M. & Bloch, D. A. Energy-converting respiratory complex I: on the way to the molecular mechanism of the proton pump. Int. J. Biochem. Cell Biol. 45, 491–511 (2013).

    CAS  PubMed  Google Scholar 

  63. Kaila, V. R. I. Long-range proton-coupled electron transfer in biological energy conversion: towards mechanistic understanding of respiratory complex I. J. R. Soc. Interface 15, 20170916 (2018).

    PubMed  PubMed Central  Google Scholar 

  64. Iverson, T. M. Catalytic mechanisms of complex II enzymes: a structural perspective. Biochim. Biophys. Acta Bioenerg. 1827, 648–657 (2013).

    CAS  Google Scholar 

  65. Sun, F. et al. Crystal structure of mitochondrial respiratory membrane protein complex II. Cell 121, 1043–1057 (2005).

    CAS  PubMed  Google Scholar 

  66. Moosavi, B., Berry, E. A., Zhu, X. L., Yang, W. C. & Yang, G. F. The assembly of succinate dehydrogenase: a key enzyme in bioenergetics. Cell. Mol. Life Sci. 76, 4023–4042 (2019).

    CAS  PubMed  Google Scholar 

  67. Huang, L. S. et al. 3-Nitropropionic acid is a suicide inhibitor of mitochondrial respiration that, upon oxidation by complex II, forms a covalent adduct with a catalytic base arginine in the active site of the enzyme. J. Biol. Chem. 281, 5965–5972 (2006).

    CAS  PubMed  Google Scholar 

  68. Scalliet, G. et al. Mutagenesis and functional studies with succinate dehydrogenase inhibitors in the wheat pathogen Mycosphaerella graminicola. PLoS ONE 7, e35429 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  69. Ruprecht, J. et al. Perturbation of the quinone-binding site of complex II alters the electronic properties of the proximal [3Fe-4S] iron-sulfur cluster. J. Biol. Chem. 286, 12756–12765 (2011).

    CAS  PubMed  PubMed Central  Google Scholar 

  70. Yankovskaya, V. et al. Architecture of succinate dehydrogenase and reactive oxygen species generation. Science 299, 700–704 (2003).

    CAS  PubMed  Google Scholar 

  71. Oyedotun, K. S., Sit, C. S. & Lemire, B. D. The Saccharomyces cerevisiae succinate dehydrogenase does not require heme for ubiquinone reduction. Biochim. Biophys. Acta Bioenerg. 1767, 1436–1445 (2007).

    CAS  Google Scholar 

  72. Blaut, M. et al. Fumarate reductase mutants of Escherichia coli that lack covalently bound flavin. J. Biol. Chem. 264, 13599–13604 (1989).

    CAS  PubMed  Google Scholar 

  73. Xia, D. et al. Crystal structure of the cytochrome bc1 complex from bovine heart mitochondria. Science 277, 60–66 (1997).

    CAS  PubMed  Google Scholar 

  74. Xia, D., Esser, L., Yu, L. & Yu, C. A. Structural basis for the mechanism of electron bifurcation at the quinol oxidation site of the cytochrome bc1 complex. Photosynthesis Res. 92, 17–34 (2007).

    CAS  Google Scholar 

  75. Sarewicz, M. & Osyczka, A. Electronic connection between the quinone and cytochrome c redox pools and its role in regulation of mitochondrial electron transport and redox signaling. Physiol. Rev. 95, 219–243 (2015).

    PubMed  PubMed Central  Google Scholar 

  76. Cooley, J. W., Roberts, A. G., Bowman, M. K., Kramer, D. M. & Daldal, F. The raised midpoint potential of the [2Fe2S] cluster of cytochrome bc1 is mediated by both the Qo site occupants and the head domain position of the Fe-S protein subunit. Biochemistry 43, 2217–2227 (2004).

    CAS  PubMed  Google Scholar 

  77. Cooley, J. W., Ohnishi, T. & Daldal, F. Binding dynamics at the quinone reduction (Qi) site influence the equilibrium interactions of the iron sulfur protein and hydroquinone oxidation (Qo) site of the cytochrome bc1 complex. Biochemistry 44, 55 (2005).

    Google Scholar 

  78. Cooley, J. W., Lee, D. W. & Daldal, F. Across membrane communication between the Qo and Q1 active sites of cytochrome bc1. Biochemistry 48, 1888–1899 (2009).

    CAS  PubMed  Google Scholar 

  79. Dikanov, S. A. et al. Identification of hydrogen bonds to the Rieske cluster through the weakly coupled nitrogens detected by electron spin echo envelope modulation spectroscopy. J. Biol. Chem. 281, 27416–27425 (2006).

    CAS  PubMed  Google Scholar 

  80. Sarewicz, M., Dutka, M., Pintscher, S. & Osyczka, A. Triplet state of the semiquinone-Rieske cluster as an intermediate of electronic bifurcation catalyzed by cytochrome bc1. Biochemistry 52, 6388–6395 (2013).

    CAS  PubMed  Google Scholar 

  81. McCurley, J. P., Miki, T., Yu, L. & Yu, C. A. EPR characterization of the cytochrome b-c1 complex from Rhodobacter sphaeroides. BBA Bioenerg. 1020, 176–186 (1990).

    CAS  Google Scholar 

  82. Sarewicz, M., Borek, A., Daldal, F., Froncisz, W. & Osyczka, A. Demonstration of short-lived complexes of cytochrome c with cytochrome bc1 by EPR spectroscopy: implications for the mechanism of interprotein electron transfer. J. Biol. Chem. 283, 24826–24836 (2008).

    CAS  PubMed  PubMed Central  Google Scholar 

  83. Zong, S. et al. UQCRFS1N assembles mitochondrial respiratory complex-III into an asymmetric 21-subunit dimer. Protein Cell 9, 586–591 (2018).

    PubMed  PubMed Central  Google Scholar 

  84. Ndi, M., Marin-Buera, L., Salvatori, R., Singh, A. P. & Ott, M. Biogenesis of the bc1 complex of the mitochondrial respiratory chain. J. Mol. Biol. 430, 3892–3905 (2018).

    CAS  PubMed  Google Scholar 

  85. Hildenbeutel, M. et al. Assembly factors monitor sequential hemylation of cytochrome b to regulate mitochondrial translation. J. Cell Biol. 205, 511–524 (2014).

    CAS  PubMed  PubMed Central  Google Scholar 

  86. Gruschke, S. et al. The Cbp3-Cbp6 complex coordinates cytochrome b synthesis with bc1 complex assembly in yeast mitochondria. J. Cell Biol. 199, 137–150 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  87. Stephan, K. & Ott, M. Timing of dimerization of the bc1 complex during mitochondrial respiratory chain assembly. Biochim. Biophys. Acta Bioenerg. 1861, 148177 (2020).

    CAS  PubMed  Google Scholar 

  88. Sánchez, E. et al. LYRM7/MZM1L is a UQCRFS1 chaperone involved in the last steps of mitochondrial complex III assembly in human cells. Biochim. Biophys. Acta 1827, 285–293 (2013).

    PubMed  Google Scholar 

  89. Fernandez-Vizarra, E. et al. Impaired complex III assembly associated with BCS1L gene mutations in isolated mitochondrial encephalopathy. Hum. Mol. Genet. 16, 1241–1252 (2007).

    CAS  PubMed  Google Scholar 

  90. Wagener, N., Ackermann, M., Funes, S. & Neupert, W. A pathway of protein translocation in mitochondria mediated by the AAA-ATPase Bcs1. Mol. Cell 44, 191–202 (2011).

    CAS  PubMed  Google Scholar 

  91. Tang, W. K. et al. Structures of AAA protein translocase Bcs1 suggest translocation mechanism of a folded protein. Nat. Struct. Mol. Biol. 27, 202–209 (2020).

    CAS  PubMed  Google Scholar 

  92. Zara, V., Conte, L. & Trumpower, B. L. Evidence that the assembly of the yeast cytochrome bc1 complex involves the formation of a large core structure in the inner mitochondrial membrane. FEBS J. 276, 1900–1914 (2009).

    CAS  PubMed  PubMed Central  Google Scholar 

  93. Bottani, E. et al. TTC19 plays a husbandry role on UQCRFS1 turnover in the biogenesis of mitochondrial respiratory complex III. Mol. Cell 67, 96–105.e4 (2017).

    CAS  PubMed  Google Scholar 

  94. Ghezzi, D. et al. Mutations in TTC19 cause mitochondrial complex III deficiency and neurological impairment in humans and flies. Nat. Genet. 43, 259–263 (2011).

    CAS  PubMed  Google Scholar 

  95. Berry, E. A., De Bari, H. & Huang, L. S. Unanswered questions about the structure of cytochrome bc1 complexes. Biochim. Biophys. Acta 1827, 1258–1277 (2013).

    CAS  PubMed  Google Scholar 

  96. Fernandez-Vizarra, E. & Zeviani, M. Mitochondrial complex III Rieske Fe-S protein processing and assembly. Cell Cycle 17, 681–687 (2018).

    CAS  PubMed  PubMed Central  Google Scholar 

  97. Vercellino, I. & Sazanov, L. Structure and assembly of mammalian mitochondrial supercomplex CIII2CIV. Nature https://doi.org/10.1038/s41586-021-03927-z (2021). First structure of mammalian supercomplex CIII2CIV.

  98. Zhang, S. et al. Mitochondrial peptide BRAWNIN is essential for vertebrate respiratory complex III assembly. Nat. Commun. 11, 1–16 (2020).

    Google Scholar 

  99. Yoshikawa, S. & Shimada, A. Reaction mechanism of cytochrome c oxidase. Chem. Rev. 115, 1936–1989 (2015).

    CAS  PubMed  Google Scholar 

  100. Timón-Gómez, A. et al. Mitochondrial cytochrome c oxidase biogenesis: recent developments. Semin. Cell Dev. Biol. 76, 163–178 (2018).

    PubMed  Google Scholar 

  101. Shinzawa-Itoh, K. et al. Structures and physiological roles of 13 integral lipids of bovine heart cytochrome c oxidase. EMBO J. 26, 1713–1725 (2007).

    CAS  PubMed  PubMed Central  Google Scholar 

  102. Zong, S. et al. Structure of the intact 14-subunit human cytochrome c oxidase. Cell Res. 28, 1026–1034 (2018).

    CAS  PubMed  PubMed Central  Google Scholar 

  103. Watson, S. A. & McStay, G. P. Functions of cytochrome c oxidase assembly factors. Int. J. Mol. Sci. 21, 1–18 (2020).

    Google Scholar 

  104. Vidoni, S. et al. MR-1S interacts with PET100 and PET117 in module-based assembly of human cytochrome c oxidase. Cell Rep. 18, 1727–1738 (2017).

    CAS  PubMed  Google Scholar 

  105. Calvo, E. et al. Functional role of respiratory supercomplexes in mice: SCAF1 relevance and segmentation of the Qpool. Sci. Adv. 6, eaba7509 (2020). SCAF1-mediated modulation of supercomplexes assembly in mice.

    CAS  PubMed  PubMed Central  Google Scholar 

  106. Diaz, F., Fukui, H., Garcia, S. & Moraes, C. T. Cytochrome c oxidase is required for the assembly/stability of respiratory complex I in mouse fibroblasts. Mol. Cell. Biol. 26, 4872–4881 (2006).

    CAS  PubMed  PubMed Central  Google Scholar 

  107. Čunátová, K. et al. Loss of COX4I1 leads to combined respiratory chain deficiency and impaired mitochondrial protein synthesis. Cells 10, 369 (2021).

    PubMed  PubMed Central  Google Scholar 

  108. Yoshikawa, S., Muramoto, K. & Shinzawa-Itoh, K. Proton-pumping mechanism of cytochrome c oxidase. Annu. Rev. Biophys. 40, 205–223 (2011).

    CAS  PubMed  Google Scholar 

  109. Abbas, Y. M., Wu, D., Bueler, S. A., Robinson, C. V. & Rubinstein, J. L. Structure of V-ATPase from the mammalian brain. Science 367, 1240–1246 (2020).

    CAS  PubMed  PubMed Central  Google Scholar 

  110. Morales-Rios, E. et al. Purification, characterization and crystallization of the F-ATPase from Paracoccus denitrificans. Open. Biol. https://doi.org/10.1098/rsob.150119 (2015).

    Article  PubMed  PubMed Central  Google Scholar 

  111. Hahn, A., Vonck, J., Mills, D. J., Meier, T. & Kühlbrandt, W. Structure, mechanism, and regulation of the chloroplast ATP synthase. Science 360, eaat4318 (2018).

    PubMed  PubMed Central  Google Scholar 

  112. Grüber, G., Manimekalai, M. S. S., Mayer, F. & Müller, V. ATP synthases from archaea: the beauty of a molecular motor. Biochim. Biophys. Acta 1837, 940–952 (2014).

    PubMed  Google Scholar 

  113. He, J. et al. Assembly of the membrane domain of ATP synthase in human mitochondria. Proc. Natl Acad. Sci. USA 115, 2988–2993 (2018).

    CAS  PubMed  PubMed Central  Google Scholar 

  114. He, J. et al. Assembly of the peripheral stalk of ATP synthase in human mitochondria. Proc. Natl Acad. Sci. USA 117, 29602–29608 (2020).

    CAS  PubMed  PubMed Central  Google Scholar 

  115. Blum, T. B., Hahn, A., Meier, T., Davies, K. M. & Kühlbrandt, W. Dimers of mitochondrial ATP synthase induce membrane curvature and self-assemble into rows. Proc. Natl Acad. Sci. USA 116, 4250–4255 (2019).

    CAS  PubMed  PubMed Central  Google Scholar 

  116. Cabezón, E., Arechaga, I., Butler, P. J. G. & Walker, J. E. Dimerization of bovine F1-ATPase by binding the inhibitor protein, IF1. J. Biol. Chem. 275, 28353–28355 (2000).

    PubMed  Google Scholar 

  117. Gu, J. et al. Cryo-EM structure of the mammalian ATP synthase tetramer bound with inhibitory protein IF1. Science 364, 1068–1075 (2019).

    CAS  PubMed  Google Scholar 

  118. Zou, H., Li, Y., Liu, X. & Wang, X. An APAf-1.cytochrome c multimeric complex is a functional apoptosome that activates procaspase-9. J. Biol. Chem. 274, 11549–11556 (1999).

    CAS  PubMed  Google Scholar 

  119. Haworth, R. A. & Hunter, D. R. The Ca2+-induced membrane transition in mitochondria. II. Nature of the Ca2+ trigger site. Arch. Biochem. Biophys. 195, 460–467 (1979).

    CAS  PubMed  Google Scholar 

  120. Schinzel, A. C. et al. Cyclophilin D is a component of mitochondrial permeability transition and mediates neuronal cell death after focal cerebral ischemia. Proc. Natl Acad. Sci. USA 102, 12005–12010 (2005).

    CAS  PubMed  PubMed Central  Google Scholar 

  121. Mnatsakanyan, N. et al. A mitochondrial megachannel resides in monomeric F1FO ATP synthase. Nat. Commun. 10, 1–11 (2019).

    CAS  Google Scholar 

  122. Davies, K. M., Blum, T. B. & Kühlbrandt, W. Conserved in situ arrangement of complex I and III2 in mitochondrial respiratory chain supercomplexes of mammals, yeast, and plants. Proc. Natl Acad. Sci. USA 115, 3024–3029 (2018). In situ structural study of supercomplex arrangement from mitochondria of different species.

    CAS  PubMed  PubMed Central  Google Scholar 

  123. Sousa, J. S., Mills, D. J., Vonck, J. & Kühlbrandt, W. Functional asymmetry and electron flow in the bovine respirasome. eLife 5, e21290 (2016).

    PubMed  PubMed Central  Google Scholar 

  124. Althoff, T., Mills, D. J., Popot, J.-L. & Kühlbrandt, W. Arrangement of electron transport chain components in bovine mitochondrial supercomplex I1III2IV1. EMBO J. 30, 4652–4664 (2011).

    CAS  PubMed  PubMed Central  Google Scholar 

  125. Maranzana, E., Barbero, G., Falasca, A. I., Lenaz, G. & Genova, M. L. Mitochondrial respiratory supercomplex association limits production of reactive oxygen species from complex I. Antioxid. Redox Signal. 19, 1469–1480 (2013).

    CAS  PubMed  PubMed Central  Google Scholar 

  126. Lopez-Fabuel, I. et al. Complex I assembly into supercomplexes determines differential mitochondrial ROS production in neurons and astrocytes. Proc. Natl Acad. Sci. USA 113, 13063–13068 (2016).

    CAS  PubMed  PubMed Central  Google Scholar 

  127. Quinlan, C. L., Perevoshchikova, I. V., Hey-Mogensen, M., Orr, A. L. & Brand, M. D. Sites of reactive oxygen species generation by mitochondria oxidizing different substrates. Redox Biol. 1, 304–312 (2013).

    CAS  PubMed  PubMed Central  Google Scholar 

  128. Hou, T. et al. NDUFAB1 confers cardio-protection by enhancing mitochondrial bioenergetics through coordination of respiratory complex and supercomplex assembly. Cell Res. 29, 754–766 (2019).

    CAS  PubMed  PubMed Central  Google Scholar 

  129. Wang, G., Popovic, B., Tao, J. & Jiang, A. Overexpression of COX7RP promotes tumor growth and metastasis by inducing ROS production in hepatocellular carcinoma cells. Am. J. Cancer Res. 10, 1366–1383 (2020).

    CAS  PubMed  PubMed Central  Google Scholar 

  130. Ikeda, K. et al. Mitochondrial supercomplex assembly promotes breast and endometrial tumorigenesis by metabolic alterations and enhanced hypoxia tolerance. Nat. Commun. 10, 1–15 (2019).

    Google Scholar 

  131. Blanchi, C., Genova, M. L., Castelli, G. P. & Lenaz, G. The mitochondrial respiratory chain is partially organized in a supercomplex assembly: hinetic evidence using flux control analysis. J. Biol. Chem. 279, 36562–36569 (2004).

    Google Scholar 

  132. Lapuente-Brun, E. et al. Supercomplex assembly determines electron flux in the mitochondrial electron transport chain. Science 340, 1567–1570 (2013). Biochemical characterization of the respiratory supercomplexes, proposing the existence of separate quinone pools.

    CAS  PubMed  Google Scholar 

  133. Fedor, J. G. & Hirst, J. Mitochondrial supercomplexes do not enhance catalysis by quinone channeling. Cell Metab. 28, 525–531.e4 (2018). Biochemical characterization of the respiratory supercomplexes, disproving the existence of separate quinone pools.

    CAS  PubMed  PubMed Central  Google Scholar 

  134. Lobo-Jarne, T. & Ugalde, C. Respiratory chain supercomplexes: structures, function and biogenesis. Semin. Cell Dev. Biol. 76, 179–190 (2018).

    CAS  PubMed  Google Scholar 

  135. Cogliati, S. et al. Mechanism of super-assembly of respiratory complexes III and IV. Nature 539, 579–582 (2016).

    CAS  PubMed  Google Scholar 

  136. Sun, D., Li, B., Qiu, R., Fang, H. & Lyu, J. Cell type-specific modulation of respiratory chain supercomplex organization. Int. J. Mol. Sci. 17, 926 (2016).

    PubMed Central  Google Scholar 

  137. Javadov, S., Jang, S., Chapa-Dubocq, X. R., Khuchua, Z. & Camara, A. K. Mitochondrial respiratory supercomplexes in mammalian cells: structural versus functional role. J. Mol. Med. 99, 57–73 (2021).

    CAS  PubMed  Google Scholar 

  138. Moreno-Lastres, D. et al. Mitochondrial complex I plays an essential role in human respirasome assembly. Cell Metab. 15, 324–335 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  139. Acín-Pérez, R., Fernández-Silva, P., Peleato, M. L., Pérez-Martos, A. & Enriquez, J. A. Respiratory active mitochondrial supercomplexes. Mol. Cell 32, 529–539 (2008).

    PubMed  Google Scholar 

  140. Fang, H. et al. A membrane arm of mitochondrial complex I sufficient to promote respirasome formation. Cell Rep. 35, 108963 (2021).

    CAS  PubMed  Google Scholar 

  141. Novack, G. V., Galeano, P., Castaño, E. M. & Morelli, L. Mitochondrial supercomplexes: physiological organization and dysregulation in age-related neurodegenerative disorders. Front. Endocrinol. 11, 600 (2020).

    Google Scholar 

  142. Ikeda, K., Shiba, S., Horie-Inoue, K., Shimokata, K. & Inoue, S. A stabilizing factor for mitochondrial respiratory supercomplex assembly regulates energy metabolism in muscle. Nat. Commun. 4, 1–9 (2013).

    Google Scholar 

  143. García-Poyatos, C. et al. Scaf1 promotes respiratory supercomplexes and metabolic efficiency in zebrafish. EMBO Rep. 21, e50287 (2020).

    PubMed  PubMed Central  Google Scholar 

  144. Shiba, S. et al. Deficiency of COX7RP, a mitochondrial supercomplex assembly promoting factor, lowers blood glucose level in mice. Sci. Rep. 7, 1–9 (2017).

    Google Scholar 

  145. Balsa, E. et al. ER and nutrient stress promote assembly of respiratory chain supercomplexes through the PERK-eIF2α Axis. Mol. Cell 74, 877–890.e6 (2019).

    CAS  PubMed  PubMed Central  Google Scholar 

  146. Pérez-Pérez, R. et al. COX7A2L is a mitochondrial complex III binding protein that stabilizes the III2+IV supercomplex without affecting respirasome formation. Cell Rep. 16, 2387–2398 (2016).

    PubMed  PubMed Central  Google Scholar 

  147. Lobo-Jarne, T. et al. Human COX7A2L regulates complex III biogenesis and promotes supercomplex organization remodeling without affecting mitochondrial bioenergetics. Cell Rep. 25, 1786–1799.e4 (2018).

    CAS  PubMed  PubMed Central  Google Scholar 

  148. Fernández-Vizarra, E. et al. SILAC-based complexome profiling dissects the structural organization of the human respiratory supercomplexes in SCAFI KO cells. Biochim. Biophys. Acta Bioenerg. 1862, 148414 (2021).

    PubMed  Google Scholar 

  149. Mourier, A., Matic, S., Ruzzenente, B., Larsson, N. G. & Milenkovic, D. The respiratory chain supercomplex organization is independent of COX7A2L isoforms. Cell Metab. 20, 1069–1075 (2014).

    CAS  PubMed  PubMed Central  Google Scholar 

  150. Ameri, K. et al. HIGD1A regulates oxygen consumption, ROS production, and AMPK activity during glucose deprivation to modulate cell survival and tumor growth. Cell Rep. 10, 891–899 (2015).

    CAS  PubMed  PubMed Central  Google Scholar 

  151. Timón-Gómez, A., Bartley-Dier, E. L., Fontanesi, F. & Barrientos, A. HIGD-driven regulation of cytochrome c oxidase biogenesis and function. Cells 9, 2620 (2020).

    PubMed Central  Google Scholar 

  152. Timón-Gómez, A., Garlich, J., Stuart, R. A., Ugalde, C. & Barrientos, A. Distinct roles of mitochondrial HIGD1A and HIGD2A in respiratory complex and supercomplex biogenesis. Cell Rep. 31, 107607 (2020).

    PubMed  Google Scholar 

  153. Hock, D. H. et al. HIGD2A is required for assembly of the COX3 module of human mitochondrial complex IV. Mol. Cell. Proteom. 19, 1145–1160 (2020).

    CAS  Google Scholar 

  154. Hayashi, T. et al. DJ-1 binds to mitochondrial complex I and maintains its activity. Biochem. Biophys. Res. Commun. 390, 667–672 (2009).

    CAS  PubMed  Google Scholar 

  155. Agip, A. N. A. et al. Cryo-EM structures of complex I from mouse heart mitochondria in two biochemically defined states. Nat. Struct. Mol. Biol. 25, 548–556 (2018).

    CAS  PubMed  PubMed Central  Google Scholar 

  156. Balsa, E. et al. NDUFA4 is a subunit of complex IV of the mammalian electron transport chain. Cell Metab. 16, 378–386 (2012).

    CAS  PubMed  Google Scholar 

  157. Pitceathly, R. D. S. et al. NDUFA4 mutations underlie dysfunction of a cytochrome c oxidase subunit linked to human neurological disease. Cell Rep. 3, 1795–1805 (2013).

    CAS  PubMed  PubMed Central  Google Scholar 

  158. Berndtsson, J. et al. Respiratory supercomplexes enhance electron transport by decreasing cytochrome c diffusion distance. EMBO Rep. 21, e51015 (2020).

    CAS  PubMed  PubMed Central  Google Scholar 

  159. Blaza, J. N., Serreli, R., Jones, A. J. Y., Mohammed, K. & Hirst, J. Kinetic evidence against partitioning of the ubiquinone pool and the catalytic relevance of respiratory-chain supercomplexes. Proc. Natl Acad. Sci. USA 111, 15735–15740 (2014).

    CAS  PubMed  PubMed Central  Google Scholar 

  160. Hackenbrock, C. R. Ultrastructural bases for metabolically linked mechanical activity in mitochondria. I. Reversible ultrastructural changes with change in metabolic steady state in isolated liver mitochondria. J. Cell Biol. 30, 269–297 (1966).

    CAS  PubMed  PubMed Central  Google Scholar 

  161. Scorrano, L. et al. A distinct pathway remodels mitochondrial cristae and mobilizes cytochrome c during apoptosis. Dev. Cell 2, 55–67 (2002).

    CAS  PubMed  Google Scholar 

  162. Cogliati, S. et al. Mitochondrial cristae shape determines respiratory chain supercomplexes assembly and respiratory efficiency. Cell 155, 160–171 (2013).

    CAS  PubMed  PubMed Central  Google Scholar 

  163. Barth, P. G. et al. An X-linked mitochondrial disease affecting cardiac muscle, skeletal muscle and neutrophil leucocytes. J. Neurol. Sci. 62, 327–355 (1983).

    CAS  PubMed  Google Scholar 

  164. Xu, Y. et al. Loss of protein association causes cardiolipin degradation in Barth syndrome. Nat. Chem. Biol. 12, 641–647 (2016).

    CAS  PubMed  PubMed Central  Google Scholar 

  165. Hirst, J. Open questions: respiratory chain supercomplexes-why are they there and what do they do? BMC Biol. 16, 111 (2018).

    CAS  PubMed  PubMed Central  Google Scholar 

  166. Dudkina, N. V., Kouřil, R., Peters, K., Braun, H. P. & Boekema, E. J. Structure and function of mitochondrial supercomplexes. Biochim. Biophys. Acta Bioenerg. 1797, 664–670 (2010).

    CAS  Google Scholar 

  167. Chaban, Y., Boekema, E. J. & Dudkina, N. V. Structures of mitochondrial oxidative phosphorylation supercomplexes and mechanisms for their stabilisation. Biochim. Biophys. Acta Bioenerg. 1837, 418–426 (2014).

    CAS  Google Scholar 

  168. Bouvette, J. et al. Beam image-shift accelerated data acquisition for near-atomic resolution single-particle cryo-electron tomography. Nat. Commun. 12, 1957 (2021).

    CAS  PubMed  PubMed Central  Google Scholar 

  169. Yang, G. et al. Atp23p and Atp10p coordinate to regulate the assembly of yeast mitochondrial ATP synthase. FASEB J. 35, e21538 (2021).

    CAS  PubMed  Google Scholar 

  170. De Grassi, A., Lanave, C. & Saccone, C. Evolution of ATP synthase subunit c and cytochrome c gene families in selected metazoan classes. Gene 371, 224–233 (2006).

    PubMed  Google Scholar 

  171. Küster, U., Bohnensack, R. & Kunz, W. Control of oxidative phosphorylation by the extramitochondrial ATP/ADP ratio. BBA Bioenerg. 440, 391–402 (1976).

    Google Scholar 

  172. Meyrat, A. & von Ballmoos, C. ATP synthesis at physiological nucleotide concentrations. Sci. Rep. 9, 1–10 (2019).

    CAS  Google Scholar 

  173. Williams, G. I. Respiratory enzymes in oxidative phosphorylation III. The steady state. J. Biol. Chem. 217, 409–427 (1955).

    PubMed  Google Scholar 

  174. Wikström, M. & Springett, R. Thermodynamic efficiency, reversibility, and degree of coupling in energy conservation by the mitochondrial respiratory chain. Commun. Biol. 3, 1–9 (2020).

    Google Scholar 

  175. Nicholls, D. G. The physiological regulation of uncoupling proteins. Biochim. Biophys. Acta Bioenerg. 1757, 459–466 (2006).

    CAS  Google Scholar 

  176. Wang, W. & Seale, P. Control of brown and beige fat development. Nat. Rev. Mol. Cell Biol. 17, 691–702 (2016).

    CAS  PubMed  PubMed Central  Google Scholar 

  177. Kory, N. et al. MCART1/SLC25A51 is required for mitochondrial NAD transport. Sci. Adv. 6, eabe5310 (2020).

    CAS  PubMed  PubMed Central  Google Scholar 

  178. Luongo, T. S. et al. SLC25A51 is a mammalian mitochondrial NAD+ transporter. Nature 588, 174–179 (2020).

    CAS  PubMed  PubMed Central  Google Scholar 

  179. Girardi, E. et al. Epistasis-driven identification of SLC25A51 as a regulator of human mitochondrial NAD import. Nat. Commun. 11, 1–9 (2020).

    Google Scholar 

  180. Ouyang, Y., Bott, A. J. & Rutter, J. Maestro of the SereNADe: SLC25A51 orchestrates mitochondrial NAD+. Trends Biochem. Sci. 46, 348–350 (2021).

    CAS  PubMed  PubMed Central  Google Scholar 

  181. Davila, A. et al. Nicotinamide adenine dinucleotide is transported into mammalian mitochondria. eLife 7, e33246 (2018).

    PubMed  PubMed Central  Google Scholar 

  182. Mills, E. L. et al. Accumulation of succinate controls activation of adipose tissue thermogenesis. Nature 560, 102–106 (2018).

    CAS  PubMed  PubMed Central  Google Scholar 

  183. Darvey, I. G. What factors are responsible for the greater yield of ATP per carbon atom when fatty acids are completely oxidised to CO2 and water compared with glucose? Biochem. Mol. Biol. Educ. 27, 209–210 (1999).

    CAS  Google Scholar 

  184. Rabinowitz, J. D. & Enerbäck, S. Lactate: the ugly duckling of energy metabolism. Nat. Metab. 2, 566–571 (2020).

    CAS  PubMed  PubMed Central  Google Scholar 

  185. Brand, M. D. The efficiency and plasticity of mitochondrial energy transduction. Biochem. Soc. Trans. 33, 897–904 (2005).

    CAS  PubMed  Google Scholar 

  186. Warburg, O. On the origin of cancer cells. Science 123, 309–314 (1956).

    CAS  PubMed  Google Scholar 

  187. DeBerardinis, R. J. & Chandel, N. S. We need to talk about the Warburg effect. Nat. Metab. 2, 127–129 (2020).

    PubMed  Google Scholar 

  188. Bennett, N. K. et al. Defining the ATPome reveals cross-optimization of metabolic pathways. Nat. Commun. 11, 1–16 (2020).

    Google Scholar 

  189. Wilson, D. F., Rumsey, W. L., Green, T. J. & Vanderkooi, J. M. The oxygen dependence of mitochondrial oxidative phosphorylation measured by a new optical method for measuring oxygen concentration. J. Biol. Chem. 263, 2712–2718 (1988).

    CAS  PubMed  Google Scholar 

  190. Lee, P., Chandel, N. S. & Simon, M. C. Cellular adaptation to hypoxia through hypoxia inducible factors and beyond. Nat. Rev. Mol. Cell Biol. 21, 268–283 (2020).

    CAS  PubMed  PubMed Central  Google Scholar 

  191. Gorman, G. S. et al. Mitochondrial diseases. Nat. Rev. Dis. Primers 2, 16081 (2016).

    Google Scholar 

  192. McFarland, R. & Turnbull, D. M. Batteries not included: diagnosis and management of mitochondrial disease. J. Intern. Med. 265, 210–228 (2009).

    CAS  PubMed  Google Scholar 

  193. Smeitink, J. A., Zeviani, M., Turnbull, D. M. & Jacobs, H. T. Mitochondrial medicine: a metabolic perspective on the pathology of oxidative phosphorylation disorders. Cell Metab. 3, 9–13 (2006).

    CAS  PubMed  Google Scholar 

  194. Ghezzi, D. & Zeviani, M. Human diseases associated with defects in assembly of OXPHOS complexes. Essays Biochem. 62, 271–286 (2018).

    PubMed  PubMed Central  Google Scholar 

  195. Frazier, A. E., Thorburn, D. R. & Compton, A. G. Mitochondrial energy generation disorders: genes, mechanisms, and clues to pathology. J. Biol. Chem. 294, 5386–5395 (2019).

    CAS  PubMed  Google Scholar 

  196. Vafai, S. B. & Mootha, V. K. Mitochondrial disorders as windows into an ancient organelle. Nature 491, 374–383 (2012).

    CAS  PubMed  Google Scholar 

  197. Schubert, M. B. & Vilarinho, L. Molecular basis of Leigh syndrome: a current look. Orphanet J. Rare Dis. 15, 1–14 (2020).

    Google Scholar 

  198. El-Hattab, A. W., Adesina, A. M., Jones, J. & Scaglia, F. MELAS syndrome: clinical manifestations, pathogenesis, and treatment options. Mol. Genet. Metab. 116, 4–12 (2015).

    CAS  PubMed  Google Scholar 

  199. Finsterer, J. & Zarrouk-Mahjoub, S. Leber’s hereditary optic neuropathy is multiorgan not mono-organ. Clin. Ophthalmol. 10, 2187–2190 (2016).

    CAS  PubMed  PubMed Central  Google Scholar 

  200. Fiedorczuk, K. & Sazanov, L. A. Mammalian mitochondrial complex I structure and disease-causing mutations. Trends Cell Biol. 28, 835–867 (2018).

    CAS  PubMed  Google Scholar 

  201. Dalla Pozza, E. et al. Regulation of succinate dehydrogenase and role of succinate in cancer. Semin. Cell Dev.Biol. 98, 4–14 (2020).

    CAS  PubMed  Google Scholar 

  202. Moosavi, B., Zhu, X. L., Yang, W. C. & Yang, G. F. Molecular pathogenesis of tumorigenesis caused by succinate dehydrogenase defect. Eur. J. Cell Biol. 99, 151057 (2020).

    CAS  PubMed  Google Scholar 

  203. Ryan, D. G. et al. Coupling Krebs cycle metabolites to signalling in immunity and cancer. Nat. Metab. 1, 16–33 (2019).

    CAS  PubMed  PubMed Central  Google Scholar 

  204. Tannahill, G. M. et al. Succinate is an inflammatory signal that induces IL-1β through HIF-1α. Nature 496, 238–242 (2013).

    CAS  PubMed  PubMed Central  Google Scholar 

  205. Mills, E. L. et al. Succinate dehydrogenase supports metabolic repurposing of mitochondria to drive inflammatory macrophages. Cell 167, 457–470 (2016).

    CAS  PubMed  PubMed Central  Google Scholar 

  206. Bonello, S. et al. Reactive oxygen species activate the HIF-1α promoter via a functional NFκB site. Arterioscler. Thromb. Vasc. Biol. 27, 755–761 (2007).

    CAS  PubMed  Google Scholar 

  207. Weinberg, S. E. et al. Mitochondrial complex III is essential for suppressive function of regulatory T cells. Nature 565, 495–499 (2019).

    CAS  PubMed  PubMed Central  Google Scholar 

  208. Fazakerley, D. J. et al. Mitochondrial CoQ deficiency is a common driver of mitochondrial oxidants and insulin resistance. eLife 7, e32111 (2018).

    PubMed  PubMed Central  Google Scholar 

  209. Alcázar-Fabra, M., Navas, P. & Brea-Calvo, G. Coenzyme Q biosynthesis and its role in the respiratory chain structure. Biochim. Biophys. Acta. 1857, 1073–1078 (2016).

    PubMed  Google Scholar 

  210. Desbats, M. A., Lunardi, G., Doimo, M., Trevisson, E. & Salviati, L. Genetic bases and clinical manifestations of coenzyme Q10 (CoQ10) deficiency. J. Inherit. Metab. Dis. 38, 145–156 (2015).

    CAS  PubMed  Google Scholar 

  211. Martínez-Reyes, I. et al. Mitochondrial ubiquinol oxidation is necessary for tumour growth. Nature 585, 288–292 (2020).

    PubMed  PubMed Central  Google Scholar 

  212. Liu, X., Kim, C. N., Yang, J., Jemmerson, R. & Wang, X. Induction of apoptotic program in cell-free extracts: requirement for dATP and cytochrome c. Cell 86, 147–157 (1996).

    CAS  PubMed  Google Scholar 

  213. Li, P. et al. Cytochrome c and dATP-dependent formation of Apaf-1/caspase-9 complex initiates an apoptotic protease cascade. Cell 91, 479–489 (1997).

    CAS  PubMed  Google Scholar 

  214. Li, K. et al. Cytochrome c deficiency causes embryonic lethality and attenuates stress-induced apoptosis. Cell 101, 389–399 (2000).

    CAS  PubMed  Google Scholar 

  215. Sazanov, L. A. A giant molecular proton pump: structure and mechanism of respiratory complex I. Nat. Rev. Mol. Cell Biol. 16, 375–388 (2015).

    CAS  PubMed  Google Scholar 

  216. Wirth, C., Brandt, U., Hunte, C. & Zickermann, V. Structure and function of mitochondrial complex I. Biochim. Biophys. Acta 1857, 902–914 (2016).

    CAS  PubMed  Google Scholar 

  217. Parey, K. et al. High-resolution cryo-EM structures of respiratory complex I: mechanism, assembly, and disease. Sci. Adv. 5, eaax9484 (2019).

    CAS  PubMed  PubMed Central  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Institute of Science and Technology Austria, Klosterneuburg, Austria

    Irene Vercellino & Leonid A. Sazanov

Authors
  1. Irene Vercellino
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Leonid A. Sazanov
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

I.V. researched data for the article and wrote the article. All authors contributed substantially to discussion of the content and reviewed and/or edited the manuscript before submission.

Corresponding author

Correspondence to Leonid A. Sazanov.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information

Nature Reviews Molecular Cell Biology thanks E. Fernandez-Vizarra, M. Zeviani and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Glossary

Reducing equivalents

Chemical species that transfer the equivalent of one electron in redox reactions.

Quinol

Reduced form of quinone. In the context of the electron transport chain, it is produced by complexes I, II and III2 and utilized by complex III2.

ATP synthase

An enzyme that catalyses the formation of ATP using ADP and inorganic phosphate. Various types of ATPases exist in nature, including A-ATPases (‘A’ stands for ‘archaeal’), F-ATPases (‘F’ stands for ‘(phosphorylation) factor’) and V-ATPases (‘V’ stands for ‘vacuolar’). The mammalian ATP synthase is an F-type ATPase.

Iron–sulfur clusters

(Fe–S clusters). Groups of iron and sulfur atoms coordinated to protein residues acting as cofactors in redox reactions due to the ability to transfer electrons from or to other Fe–S clusters or different types of donors/acceptors while undergoing oxidation and reduction cycles. The xFe–yS nomenclature refers to the number of Fe (x) and S (y) atoms in the cluster.

Haem groups

Redox cofactors featuring an iron atom at the centre of a porphyrin structure. The iron atom can undergo cycles of oxidoreduction, thereby transferring electrons from the donor to acceptors along the electron transport chain. There are three types of haems in the electron transport chain, characterized by different substituents on the porphyrin ring: haems a (a and a3) of complex IV, haems b (bH and bL) of complex III2, haem c of cytochrome c and haem c1 of complex III2.

E-channel

Group of charged residues (mostly glutamates (E)) located within subunits ND1, ND3, ND6 and ND4L of the complex I membrane arm involved in the coupling mechanism of quinone reduction to proton translocation.

Brown adipose tissue

Subtype of fat tissue characterized by a dark colour, as opposed to the normal white appearance, devoted to thermogenesis (via the uncoupling of proton gradient dissipation from ATP synthesis) instead of energy storage. Brown adipose tissue thus contains a lot more (brown) mitochondria than (white) lipid droplets.

Oncometabolite

Substrate of metabolic reactions whose aberrant accumulation triggers cancer-related pathways.

Epithelial–mesenchymal transition

Biological process typical of embryonic development, but also observed in cancer, by which epithelial cells acquire mesenchymal properties (for example, losing apicobasal polarity and increasing their motility).

Paragangliomas and phaeochromocytomas

Paragangliomas are a rare type of neuroendocrine cancer growing around ganglia (groups of neuronal bodies and glial cells) in the head, neck, torso and abdomen. Specifically, when affecting the adrenal glands, they are called ‘phaeochromocytomas’.

Insulin resistance

Pathological condition in which cells do not respond to insulin, thereby not internalizing and utilizing glucose. This phenomenon is correlated with the development of type 2 diabetes.

Caspase

Refers to a family of proteases activated by various stimuli and responsible for the apoptotic response in cells.

Electrostatic wave

Mechanism of signal transduction along the membrane arm of complex I by which the change in the charge status of key polar residues drives proton translocation.

Midpoint potential

Electric potential at which the oxidized and reduced components of a redox reaction are at equilibrium (that is, the midpoint of a redox titration).

Rieske iron–sulfur protein

(ISP). Membrane-anchored catalytic subunit of complex III2 shuttling electrons from quinol bound at haem bL to cytochrome c1 via its iron–sulfur cluster.

Low-potential redox chain

A pathway for electron transfer within complex III2 which goes from haem bL to haem bH. It shows low redox potential.

High-potential redox chain

A pathway for electron transfer within complex III2 that goes from the ISP to cytochrome c1. It shows high redox potential.

Electron paramagnetic resonance

Spectroscopic technique detecting unpaired electrons by the application of a magnetic field. In bioenergetics, it is used to study radicals, such as the quinone intermediates between fully oxidized and fully reduced states, as well as the electron transfer through transition metals in iron–sulfur clusters, haems and copper centres.

AMPK signalling

A pathway of intracellular reactions starting from AMPK (AMP-activated kinase), a sensor of the ATP levels. The signalling cascade starting from AMPK thus responds to the energetic demands of the cell and it triggers a high variety of responses pertaining to metabolism, growth, autophagy and cell polarity.

Copper centre

Prosthetic group composed of copper ions. Among the electron transport chain components, complex IV has two such centres involved in electron transfer.

c-ring

Membrane-embedded domain of ATP synthase formed by multiple copies of subunit c, arranged in the shape of a ring. The number of copies differs across species, thereby changing the diameter of the ring: mammalian ATP synthase has eight copies.

IF1

Inhibitory factor 1 (IF1) of ATP synthase involved in the prevention of ATP hydrolysis due to reverse functioning of the enzyme.

Mitochondrial cristae

The ultrastructure of the inner mitochondrial membrane, characterized by deep invaginations, increasing the overall surface of the inner mitochondrial membrane. It is guided by the arrangement of dimers of ATP synthase in rows that impose the membrane curvature.

Permeability transition pore

(PTP). Channel-like proteinaceous pore located in the inner mitochondrial membrane responsible for leakage of large molecules (up to 1.5 kDa) from the mitochondrial matrix.

Cyclophilin D

Mitochondrial peptidyl-prolyl cis–trans isomerase and a member of the cyclophilin family, a group of proteins able to bind the antifungal peptide cyclosporin A. Cyclophilins are involved in protein folding, signal transduction and the immune system. Although the precise role of cyclophilin D is not clear, it is known to interact with ATP synthase and mediate the opening of the permeability transition pore.

Substrate channelling

Metabolic phenomenon by which the reaction product of an enzyme is directly processed as a substrate by another enzyme without being exchanged with the external solution.

Endoplasmic reticulum stress

Aberrant condition characterized by the accumulation of unfolded proteins in the lumen of the endoplasmic reticulum

Hypoxia-inducible factor 1

Transcription factor primarily involved in the cellular response to hypoxia.

Metabolic flux control analysis

Mathematical description of a metabolic path where every enzymatic component is given a coefficient that describes the extent of its control over the pathway by correlating changes in the enzyme activity with changes in the flux rate.

Submitochondrial particles

Inverted vesicles of the inner mitochondrial membrane, obtained after disruption of the outer mitochondrial membrane via different mechanisms, such as osmotic shock, cycles of freezing and thawing or sonication.

Ischaemia–reperfusion injury

Pathological cellular response to reoxygenation of a tissue (reperfusion) after a period of hypoxia (ischaemia). At the molecular level, this phenomenon is characterized by an increase in the production of reactive oxygen species and activation of the caspase pathway, eventually leading to cell death.

Barth syndrome

A rare genetic disease, affecting mainly male individuals, characterized by neuromuscular deficiencies and associated with aberrant cardiolipin metabolism.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Vercellino, I., Sazanov, L.A. The assembly, regulation and function of the mitochondrial respiratory chain. Nat Rev Mol Cell Biol 23, 141–161 (2022). https://doi.org/10.1038/s41580-021-00415-0

Download citation

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41580-021-00415-0

This article is cited by

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing