Skip to main content

Thank you for visiting 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.

Anti-apoptotic MCL-1 localizes to the mitochondrial matrix and couples mitochondrial fusion to respiration

This article has been updated


MCL-1, an anti-apoptotic BCL-2 family member that is essential for the survival of multiple cell lineages, is also among the most highly amplified genes in cancer. Although MCL-1 is known to oppose cell death, precisely how it functions to promote survival of normal and malignant cells is poorly understood. Here, we report that different forms of MCL-1 reside in distinct mitochondrial locations and exhibit separable functions. On the outer mitochondrial membrane, an MCL-1 isoform acts like other anti-apoptotic BCL-2 molecules to antagonize apoptosis, whereas an amino-terminally truncated isoform of MCL-1 that is imported into the mitochondrial matrix is necessary to facilitate normal mitochondrial fusion, ATP production, membrane potential, respiration, cristae ultrastructure and maintenance of oligomeric ATP synthase. Our results provide insight into how the surprisingly diverse salutary functions of MCL-1 may control the survival of both normal and cancer cells.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Deletion of Mcl-1 results in mitochondrial morphology defects.
Figure 2: MCL-1 resides in different submitochondrial localizations.
Figure 3: MCL-1 mutants restrict mitochondrial localization.
Figure 4: Anti-apoptotic activity of MCL-1 requires localization to the OMM.
Figure 5: Lacking matrix-localized MCL-1 results in mitochondrial IMM structure and fusion defects.
Figure 6: MCL-1 regulates mitochondrial bioenergetics.

Change history

  • 17 May 2012

    In the version of this article initially published online, the x axes for Fig. 4b,c were incorrectly labelled. The correct units are μM. This has been corrected.


  1. 1

    Danial, N. N. & Korsmeyer, S. J. Cell death: critical control points. Cell 116, 205–219 (2004).

    CAS  Article  Google Scholar 

  2. 2

    Cory, S. & Adams, J. M. The Bcl2 family: regulators of the cellular life-or-death switch. Nat. Rev. Cancer 2, 647–656 (2002).

    CAS  Article  Google Scholar 

  3. 3

    Youle, R. J. & Strasser, A. The BCL-2 protein family: opposing activities that mediate cell death. Nat. Rev. Mol. Cell Biol. 9, 47–59 (2008).

    CAS  Article  Google Scholar 

  4. 4

    Wei, M. C. et al. Proapoptotic BAX and BAK: a requisite gateway to mitochondrial dysfunction and death. Science 292, 727–730 (2001).

    CAS  Article  Google Scholar 

  5. 5

    Goldstein, J. C., Waterhouse, N. J., Juin, P., Evan, G. I. & Green, D. R. The coordinate release of cytochrome c during apoptosis is rapid, complete and kinetically invariant. Nat. Cell Biol. 2, 156–162 (2000).

    CAS  Article  Google Scholar 

  6. 6

    Cheng, E. H. et al. BCL-2, BCL-X(L) sequester BH3 domain-only molecules preventing BAX- and BAK-mediated mitochondrial apoptosis. Mol. Cell 8, 705–711 (2001).

    CAS  Article  Google Scholar 

  7. 7

    Zong, W. X., Lindsten, T., Ross, A. J., MacGregor, G. R. & Thompson, C. B. BH3-only proteins that bind pro-survival Bcl-2 family members fail to induce apoptosis in the absence of Bax and Bak. Genes Dev. 15, 1481–1486 (2001).

    CAS  Article  Google Scholar 

  8. 8

    Frey, T. G. & Mannella, C. A. The internal structure of mitochondria. Trends Biochem. Sci. 25, 319–324 (2000).

    CAS  Article  Google Scholar 

  9. 9

    Chan, D. C. Mitochondrial dynamics in disease. New Engl. J. Med. 356, 1707–1709 (2007).

    CAS  Article  Google Scholar 

  10. 10

    Chen, H. & Chan, D. C. Emerging functions of mammalian mitochondrial fusion and fission. Hum. Mol. Genet. 14 (Spec no. 2), R283–R289 (2005).

    CAS  Article  Google Scholar 

  11. 11

    Mitra, K., Wunder, C., Roysam, B., Lin, G. & Lippincott-Schwartz, J. A hyperfused mitochondrial state achieved at G1-S regulates cyclin E buildup and entry into S phase. Proc. Natl Acad. Sci. USA 106, 11960–11965 (2009).

    CAS  Article  Google Scholar 

  12. 12

    Chen, H. et al. Mitofusins Mfn1 and Mfn2 coordinately regulate mitochondrial fusion and are essential for embryonic development. J. Cell Biol. 160, 189–200 (2003).

    CAS  Article  Google Scholar 

  13. 13

    Bleazard, W. et al. The dynamin-related GTPase Dnm1 regulates mitochondrial fission in yeast. Nat. Cell Biol. 1, 298–304 (1999).

    CAS  Article  Google Scholar 

  14. 14

    Rinkenberger, J. L., Horning, S., Klocke, B., Roth, K. & Korsmeyer, S. J. Mcl-1 deficiency results in peri-implantation embryonic lethality. Genes Dev. 14, 23–27 (2000).

    CAS  PubMed  PubMed Central  Google Scholar 

  15. 15

    Opferman, J. T. et al. Development and maintenance of B and T lymphocytes requires antiapoptotic MCL-1. Nature 426, 671–676 (2003).

    CAS  Article  Google Scholar 

  16. 16

    Dzhagalov, I., Dunkle, A. & He, Y. W. The anti-apoptotic Bcl-2 family member Mcl-1 promotes T lymphocyte survival at multiple stages. J. Immunol. 181, 521–528 (2008).

    CAS  Article  Google Scholar 

  17. 17

    Opferman, J. T. et al. Obligate role of anti-apoptotic MCL-1 in the survival of hematopoietic stem cells. Science 307, 1101–1104 (2005).

    CAS  Article  Google Scholar 

  18. 18

    Dzhagalov, I., St John, A. & He, Y. W. The antiapoptotic protein Mcl-1 is essential for the survival of neutrophils but not macrophages. Blood 109, 1620–1626 (2007).

    CAS  Article  Google Scholar 

  19. 19

    Steimer, D. A. et al. Selective roles for antiapoptotic MCL-1 during granulocyte development and macrophage effector function. Blood 113, 2805–2815 (2009).

    CAS  Article  Google Scholar 

  20. 20

    Arbour, N. et al. Mcl-1 is a key regulator of apoptosis during CNS development and after DNA damage. J. Neurosci. 28, 6068–6078 (2008).

    CAS  Article  Google Scholar 

  21. 21

    Beroukhim, R. et al. The landscape of somatic copy-number alteration across human cancers. Nature 463, 899–905 (2010).

    CAS  Article  Google Scholar 

  22. 22

    Wei, G. et al. Gene expression-based chemical genomics identifies rapamycin as a modulator of MCL1 and glucocorticoid resistance. Cancer Cell 10, 331–342 (2006).

    CAS  Article  Google Scholar 

  23. 23

    Wuilleme-Toumi, S. et al. Mcl-1 is overexpressed in multiple myeloma and associated with relapse and shorter survival. Leukemia 19, 1248–1252 (2005).

    CAS  Article  Google Scholar 

  24. 24

    Vogel, F., Bornhovd, C., Neupert, W. & Reichert, A. S. Dynamic subcompartmentalization of the mitochondrial inner membrane. J. Cell Biol. 175, 237–247 (2006).

    CAS  Article  Google Scholar 

  25. 25

    Gilkerson, R. W., Selker, J. M. & Capaldi, R. A. The cristal membrane of mitochondria is the principal site of oxidative phosphorylation. FEBS Lett. 546, 355–358 (2003).

    CAS  Article  Google Scholar 

  26. 26

    Maurer, U., Charvet, C., Wagman, A. S., Dejardin, E. & Green, D. R. Glycogen synthase kinase-3 regulates mitochondrial outer membrane permeabilization and apoptosis by destabilization of MCL-1. Mol. Cell 21, 749–760 (2006).

    CAS  Article  Google Scholar 

  27. 27

    Domina, A. M., Vrana, J. A., Gregory, M. A., Hann, S. R. & Craig, R. W. MCL1 is phosphorylated in the PEST region and stabilized upon ERK activation in viable cells, and at additional sites with cytotoxic okadaic acid or taxol. Oncogene 23, 5301–5315 (2004).

    CAS  Article  Google Scholar 

  28. 28

    Morel, C., Carlson, S. M., White, F. M. & Davis, R. J. Mcl-1 integrates the opposing actions of signaling pathways that mediate survival and apoptosis. Mol. Cell Biol. 29, 3845–3852 (2009).

    CAS  Article  Google Scholar 

  29. 29

    Warr, M. R. & Shore, G. C. Unique biology of Mcl-1: therapeutic opportunities in cancer. Curr. Mol. Med. 8, 138–147 (2008).

    CAS  Article  Google Scholar 

  30. 30

    Kojima, S., Hyakutake, A., Koshikawa, N., Nakagawara, A. & Takenaga, K. MCL-1V, a novel mouse antiapoptotic MCL-1 variant, generated by RNA splicing at a non-canonical splicing pair. Biochem. Biophys. Res. Commun. 391, 492–497 (2010).

    CAS  Article  Google Scholar 

  31. 31

    De Biasio, A. et al. N-terminal truncation of antiapoptotic MCL1, but not G2/M-induced phosphorylation, is associated with stabilization and abundant expression in tumor cells. J. Biol. Chem. 282, 23919–23936 (2007).

    CAS  Article  Google Scholar 

  32. 32

    Huang, C. R. & Yang-Yen, H. F. The fast-mobility isoform of mouse Mcl-1 is a mitochondrial matrix-localized protein with attenuated anti-apoptotic activity. FEBS Lett. 584, 3323–3330 (2010).

    CAS  Article  Google Scholar 

  33. 33

    Schmidt, O., Pfanner, N. & Meisinger, C. Mitochondrial protein import: from proteomics to functional mechanisms. Nat. Rev. Mol. Cell Biol. 11, 655–667 (2010).

    CAS  Article  Google Scholar 

  34. 34

    Pfanner, N., Muller, H. K., Harmey, M. A. & Neupert, W. Mitochondrial protein import: involvement of the mature part of a cleavable precursor protein in the binding to receptor sites. EMBO J. 6, 3449–3454 (1987).

    CAS  Article  Google Scholar 

  35. 35

    Karbowski, M. et al. Quantitation of mitochondrial dynamics by photolabeling of individual organelles shows that mitochondrial fusion is blocked during the Bax activation phase of apoptosis. J. Cell Biol. 164, 493–499 (2004).

    CAS  Article  Google Scholar 

  36. 36

    Wallace, D. C. Mitochondrial diseases in man and mouse. Science 283, 1482–1488 (1999).

    CAS  Article  Google Scholar 

  37. 37

    Reitzer, L. J., Wice, B. M. & Kennell, D. Evidence that glutamine, not sugar, is the major energy source for cultured HeLa cells. J. Biol. Chem. 254, 2669–2676 (1979).

    CAS  PubMed  Google Scholar 

  38. 38

    Rossignol, R. et al. Energy substrate modulates mitochondrial structure and oxidative capacity in cancer cells. Cancer Res. 64, 985–993 (2004).

    CAS  Article  Google Scholar 

  39. 39

    Ferrick, D. A., Neilson, A. & Beeson, C. Advances in measuring cellular bioenergetics using extracellular flux. Drug Discov. Today 13, 268–274 (2008).

    CAS  Article  Google Scholar 

  40. 40

    Acin-Perez, R., Fernandez-Silva, P., Peleato, M. L., Perez-Martos, A. & Enriquez, J. A. Respiratory active mitochondrial supercomplexes. Mol. Cell 32, 529–539 (2008).

    CAS  Article  Google Scholar 

  41. 41

    Genova, M. L. et al. Is supercomplex organization of the respiratory chain required for optimal electron transfer activity? Biochim. Biophys. Acta 1777, 740–746 (2008).

    CAS  Article  Google Scholar 

  42. 42

    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  Article  Google Scholar 

  43. 43

    Krause, F., Reifschneider, N. H., Goto, S. & Dencher, N. A. Active oligomeric ATP synthases in mammalian mitochondria. Biochem. Biophys. Res. Commun. 329, 583–590 (2005).

    CAS  Article  Google Scholar 

  44. 44

    Giraud, M. F. et al. Is there a relationship between the supramolecular organization of the mitochondrial ATP synthase and the formation of cristae? Biochim. Biophys. Acta 1555, 174–180 (2002).

    CAS  Article  Google Scholar 

  45. 45

    Thomas, D. et al. Supramolecular organization of the yeast F1Fo-ATP synthase. Biol. Cell 100, 591–601 (2008).

    CAS  Article  Google Scholar 

  46. 46

    Gomes, L. C., Di Benedetto, G. & Scorrano, L. During autophagy mitochondria elongate, are spared from degradation and sustain cell viability. Nat. Cell Biol. 13, 589–598 (2011).

    CAS  Article  Google Scholar 

  47. 47

    Paumard, P. et al. The ATP synthase is involved in generating mitochondrial cristae morphology. EMBO J. 21, 221–230 (2002).

    CAS  Article  Google Scholar 

  48. 48

    Bornhovd, C., Vogel, F., Neupert, W. & Reichert, A. S. Mitochondrial membrane potential is dependent on the oligomeric state of F1F0-ATP synthase supracomplexes. J. Biol. Chem. 281, 13990–13998 (2006).

    Article  Google Scholar 

  49. 49

    Kozopas, K. M., Yang, T., Buchan, H. L., Zhou, P. & Craig, R. W. MCL1, a gene expressed in programmed myeloid cell differentiation, has sequence similarity to BCL2. Proc. Natl Acad. Sci. USA 90, 3516–3520 (1993).

    CAS  Article  Google Scholar 

  50. 50

    Krajewski, S. et al. Immunohistochemical analysis of Mcl-1 protein in human tissues. Differential regulation of Mcl-1 and Bcl-2 protein production suggests a unique role for Mcl-1 in control of programmed cell death in vivo. Am. J. Pathol. 146, 1309–1319 (1995).

    CAS  PubMed  PubMed Central  Google Scholar 

  51. 51

    Yang, T., Kozopas, K. M. & Craig, R. W. The intracellular distribution and pattern of expression of Mcl-1 overlap with, but are not identical to, those of Bcl-2. J. Cell Biol. 128, 1173–1184 (1995).

    CAS  Article  Google Scholar 

  52. 52

    Chen, H. et al. Mitochondrial fusion is required for mtDNA stability in skeletal muscle and tolerance of mtDNA mutations. Cell 141, 280–289 (2010).

    CAS  Article  Google Scholar 

  53. 53

    Velours, J., Dautant, A., Salin, B., Sagot, I. & Brethes, D. Mitochondrial F1F0-ATP synthase and organellar internal architecture. Int. J. Biochem. Cell Biol. 41, 1783–1789 (2009).

    CAS  Article  Google Scholar 

  54. 54

    Deberardinis, R. J., Sayed, N., Ditsworth, D. & Thompson, C. B. Brick by brick: metabolism and tumor cell growth. Curr. Opin. Genet. Dev. 18, 54–61 (2008).

    CAS  Article  Google Scholar 

  55. 55

    Stewart, D. P. et al. Ubiquitin-independent degradation of antiapoptotic MCL-1. Mol. Cell Biol. 30, 3099–3110 (2010).

    CAS  Article  Google Scholar 

  56. 56

    Koopman, W. J. et al. Inhibition of complex I of the electron transport chain causes O2.-mediated mitochondrial outgrowth. Am. J. Physiol. Cell Physiol. 288, C1440–C1450 (2005).

    CAS  Article  Google Scholar 

  57. 57

    Peters, P. J., Bos, E. & Griekspoor, A. Cryo-immunogold electron microscopy. Curr. Protoc. Cell. Biol. Chapter 4 (2006) Unit 4 7.

  58. 58

    Frost, M. T., Wang, Q., Moncada, S. & Singer, M. Hypoxia accelerates nitric oxide-dependent inhibition of mitochondrial complex I in activated macrophages. Am. J. Physiol. Regul. Integr. Comp. Physiol. 288, R394–R400 (2005).

    CAS  Article  Google Scholar 

  59. 59

    Miyadera, H. et al. Atpenins, potent and specific inhibitors of mitochondrial complex II (succinate-ubiquinone oxidoreductase). Proc. Natl Acad. Sci. USA 100, 473–477 (2003).

    CAS  Article  Google Scholar 

  60. 60

    Miro, O. et al. Cytochrome c oxidase assay in minute amounts of human skeletal muscle using single wavelength spectrophotometers. J. Neurosci. Methods 80, 107–111 (1998).

    CAS  Article  Google Scholar 

  61. 61

    Hinman, L. M. & Blass, J. P. An NADH-linked spectrophotometric assay for pyruvate dehydrogenase complex in crude tissue homogenates. J. Biol. Chem. 256, 6583–6586 (1981).

    CAS  PubMed  Google Scholar 

  62. 62

    Fernandez-Vizarra, E., Lopez-Perez, M. J. & Enriquez, J. A. Isolation of biogenetically competent mitochondria from mammalian tissues and cultured cells. Methods 26, 292–297 (2002).

    Article  Google Scholar 

Download references


We thank the St Jude Cell and Tissue Imaging Facility for assistance with live-cell imaging and S. Frase for assistance with electron micrographs; the W. M. Keck Foundation Biotechnology Resource Laboratory at Yale University for Edman sequencing; B. Xia, E. Parganas and D. Gable for technical assistance; C. Shaner for animal husbandry; and members of the St Jude Biochemistry Department, S. Oakes, J. Ihle and C. Sherr for helpful discussions. J.T.O. is supported by the Pew Scholars Program in the Biomedical Sciences; the National Institutes of Health HL-102175; the American Cancer Society RSG-10-255-01-LIB; a Cancer Center Support Grant P30CA021765; and the American Lebanese Syrian Associated Charities of St Jude Children’s Research Hospital.

Author information




R.M.P. and J.T.O. conceived the study, designed the experiments and wrote the manuscript. R.M.P. performed the experiments, analysed data and prepared figures. D.P.S., B.K. and M.B. generated reagents and performed experiments. J.L. and J.D.S. carried out electron-transport-chain enzymatic assays. J.T. assisted in imaging data acquisition and quantification of mitochondrial morphology. M.M.C. and R.J.Y. carried out pilot experiments on mitochondrial morphology and provided reagents. S.P. assisted in acquisition of immunofluorescence micrographs. S.M. and D.R.G. carried out experiments on oxygen consumption and provided reagents. J.T.O. supervised the project.

Corresponding author

Correspondence to Joseph T. Opferman.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

Supplementary Information (PDF 569 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Perciavalle, R., Stewart, D., Koss, B. et al. Anti-apoptotic MCL-1 localizes to the mitochondrial matrix and couples mitochondrial fusion to respiration. Nat Cell Biol 14, 575–583 (2012).

Download citation

Further reading


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