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Complete subunit architecture of the proteasome regulatory particle

Abstract

The proteasome is the major ATP-dependent protease in eukaryotic cells, but limited structural information restricts a mechanistic understanding of its activities. The proteasome regulatory particle, consisting of the lid and base subcomplexes, recognizes and processes polyubiquitinated substrates. Here we used electron microscopy and a new heterologous expression system for the lid to delineate the complete subunit architecture of the regulatory particle from yeast. Our studies reveal the spatial arrangement of ubiquitin receptors, deubiquitinating enzymes and the protein unfolding machinery at subnanometre resolution, outlining the substrate’s path to degradation. Unexpectedly, the ATPase subunits within the base unfoldase are arranged in a spiral staircase, providing insight into potential mechanisms for substrate translocation through the central pore. Large conformational rearrangements of the lid upon holoenzyme formation suggest allosteric regulation of deubiquitination. We provide a structural basis for the ability of the proteasome to degrade a diverse set of substrates and thus regulate vital cellular processes.

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Figure 1: The lid subcomplex within the holoenzyme assembly.
Figure 2: Three-dimensional reconstructions of the recombinant lid subcomplex and the yeast 26S proteasome.
Figure 3: Localization of Rpn1 and Rpn2, and ubiquitin-interacting subunits.
Figure 4: Conformational rearrangements of the lid subcomplex upon integration into the holoenzyme.
Figure 5: Structural features of the base ATPase subunits.
Figure 6: Model for the recognition, deubiquitination and engagement of a polyubiquitinated substrate by the 26S proteasome.

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Accession codes

Data deposits

The cryoelectron microscopy density map for the 26S proteasome can be found at the Electron Microscopy Data Bank under accession number EMD-1992. The negative stain reconstructions of the recombinantly expressed and yeast-purified lid have been assigned accession numbers EMD-1993 and EMD-1994, respectively.

References

  1. Finley, D. Recognition and processing of ubiquitin-protein conjugates by the proteasome. Annu. Rev. Biochem. 78, 477–513 (2009)

    Article  CAS  Google Scholar 

  2. Glickman, M. H., Rubin, D. M., Fried, V. A. & Finley, D. The regulatory particle of the Saccharomyces cerevisiae proteasome. Mol. Cell. Biol. 18, 3149–3162 (1998)

    Article  CAS  Google Scholar 

  3. Thrower, J. S., Hoffman, L., Rechsteiner, M. & Pickart, C. M. Recognition of the polyubiquitin proteolytic signal. EMBO J. 19, 94–102 (2000)

    Article  CAS  Google Scholar 

  4. Groll, M. et al. A gated channel into the proteasome core particle. Nature Struct. Biol. 7, 1062–1067 (2000)

    Article  CAS  Google Scholar 

  5. Smith, D. M. et al. Docking of the proteasomal ATPases’ carboxyl termini in the 20S proteasome’s α ring opens the gate for substrate entry. Mol. Cell 27, 731–744 (2007)

    Article  CAS  Google Scholar 

  6. Yao, T. & Cohen, R. E. A cryptic protease couples deubiquitination and degradation by the proteasome. Nature 419, 403–407 (2002)

    Article  ADS  CAS  Google Scholar 

  7. Verma, R. et al. Role of Rpn11 metalloprotease in deubiquitination and degradation by the 26S proteasome. Science 298, 611–615 (2002)

    Article  ADS  CAS  Google Scholar 

  8. Tomko, R. J., Jr, Funakoshi, M., Schneider, K., Wang, J. & Hochstrasser, M. Heterohexameric ring arrangement of the eukaryotic proteasomal ATPases: implications for proteasome structure and assembly. Mol. Cell 38, 393–403 (2010)

    Article  CAS  Google Scholar 

  9. Rabl, J. et al. Mechanism of gate opening in the 20S proteasome by the proteasomal ATPases. Mol. Cell 30, 360–368 (2008)

    Article  CAS  Google Scholar 

  10. Gillette, T. G., Kumar, B., Thompson, D., Slaughter, C. A. & DeMartino, G. N. Differential roles of the COOH termini of AAA subunits of PA700 (19 S regulator) in asymmetric assembly and activation of the 26 S proteasome. J. Biol. Chem. 283, 31813–31822 (2008)

    Article  CAS  Google Scholar 

  11. da Fonseca, P. C. & Morris, E. P. Structure of the human 26S proteasome: subunit radial displacements open the gate into the proteolytic core. J. Biol. Chem. 283, 23305–23314 (2008)

    Article  CAS  Google Scholar 

  12. Elsasser, S. et al. Proteasome subunit Rpn1 binds ubiquitin-like protein domains. Nature Cell Biol. 4, 725–730 (2002)

    Article  CAS  Google Scholar 

  13. Gomez, T. A., Kolawa, N., Gee, M., Sweredoski, M. J. & Deshaies, R. J. Identification of a functional docking site in the Rpn1 LRR domain for the UBA-UBL domain protein Ddi1. BMC Biol. 9, 33 (2011)

    Article  CAS  Google Scholar 

  14. Leggett, D. S. et al. Multiple associated proteins regulate proteasome structure and function. Mol. Cell 10, 495–507 (2002)

    Article  CAS  Google Scholar 

  15. Bohn, S. et al. Structure of the 26S proteasome from Schizosaccharomyces pombe at subnanometer resolution. Proc. Natl Acad. Sci. USA 107, 20992–20997 (2010)

    Article  ADS  CAS  Google Scholar 

  16. Nickell, S. et al. Insights into the molecular architecture of the 26S proteasome. Proc. Natl Acad. Sci. USA 106, 11943–11947 (2009)

    Article  ADS  CAS  Google Scholar 

  17. Förster, F. et al. An atomic model AAA-ATPase/20S core particle sub-complex of the 26S proteasome. Biochem. Biophys. Res. Commun. 388, 228–233 (2009)

    Article  Google Scholar 

  18. Xu, P. et al. Quantitative proteomics reveals the function of unconventional ubiquitin chains in proteasomal degradation. Cell 137, 133–145 (2009)

    Article  CAS  Google Scholar 

  19. Inobe, T., Fishbain, S., Prakash, S. & Matouschek, A. Defining the geometry of the two-component proteasome degron. Nature Chem. Biol. 7, 161–167 (2011)

    Article  CAS  Google Scholar 

  20. Tian, G. et al. An asymmetric interface between the regulatory and core particles of the proteasome. Nature Struct. Mol. Biol. 18, 1259–1267 (2011)

    Article  CAS  Google Scholar 

  21. Effantin, G., Rosenzweig, R., Glickman, M. H. & Steven, A. C. Electron microscopic evidence in support of α-solenoid models of proteasomal subunits Rpn1 and Rpn2. J. Mol. Biol. 386, 1204–1211 (2009)

    Article  CAS  Google Scholar 

  22. Zhang, F. et al. Structural insights into the regulatory particle of the proteasome from Methanocaldococcus jannaschii. Mol. Cell 34, 473–484 (2009)

    Article  Google Scholar 

  23. Hamazaki, J. et al. A novel proteasome interacting protein recruits the deubiquitinating enzyme UCH37 to 26S proteasomes. EMBO J. 25, 4524–4536 (2006)

    Article  CAS  Google Scholar 

  24. Schreiner, P. et al. Ubiquitin docking at the proteasome through a novel pleckstrin-homology domain interaction. Nature 453, 548–552 (2008)

    Article  ADS  CAS  Google Scholar 

  25. Glickman, M. H. et al. A subcomplex of the proteasome regulatory particle required for ubiquitin-conjugate degradation and related to the COP9-signalosome and eIF3. Cell 94, 615–623 (1998)

    Article  CAS  Google Scholar 

  26. Verma, R., Oania, R., Graumann, J. & Deshaies, R. J. Multiubiquitin chain receptors define a layer of substrate selectivity in the ubiquitin-proteasome system. Cell 118, 99–110 (2004)

    Article  CAS  Google Scholar 

  27. Glynn, S. E., Martin, A., Nager, A. R., Baker, T. A. & Sauer, R. T. Structures of asymmetric ClpX hexamers reveal nucleotide-dependent motions in a AAA+ protein-unfolding machine. Cell 139, 744–756 (2009)

    Article  CAS  Google Scholar 

  28. Maillard, R. A. et al. ClpX(P) generates mechanical force to unfold and translocate its protein substrates. Cell 145, 459–469 (2011)

    Article  CAS  Google Scholar 

  29. Aubin-Tam, M. E., Olivares, A. O., Sauer, R. T., Baker, T. A. & Lang, M. J. Single-molecule protein unfolding and translocation by an ATP-fueled proteolytic machine. Cell 145, 257–267 (2011)

    Article  CAS  Google Scholar 

  30. Martin, A., Baker, T. A. & Sauer, R. T. Rebuilt AAA + motors reveal operating principles for ATP-fuelled machines. Nature 437, 1115–1120 (2005)

    Article  ADS  CAS  Google Scholar 

  31. Hersch, G. L., Burton, R. E., Bolon, D. N., Baker, T. A. & Sauer, R. T. Asymmetric interactions of ATP with the AAA+ ClpX6 unfoldase: allosteric control of a protein machine. Cell 121, 1017–1027 (2005)

    Article  CAS  Google Scholar 

  32. Thomsen, N. D. & Berger, J. M. Running in reverse: the structural basis for translocation polarity in hexameric helicases. Cell 139, 523–534 (2009)

    Article  CAS  Google Scholar 

  33. Enemark, E. J. & Joshua-Tor, L. Mechanism of DNA translocation in a replicative hexameric helicase. Nature 442, 270–275 (2006)

    Article  ADS  CAS  Google Scholar 

  34. Riedinger, C. et al. Structure of Rpn10 and its interactions with polyubiquitin chains and the proteasome subunit Rpn12. J. Biol. Chem. 285, 33992–34003 (2010)

    Article  CAS  Google Scholar 

  35. Eddins, M. J., Varadan, R., Fushman, D., Pickart, C. M. & Wolberger, C. Crystal structure and solution NMR studies of Lys48-linked tetraubiquitin at neutral pH. J. Mol. Biol. 367, 204–211 (2007)

    Article  CAS  Google Scholar 

  36. Cook, W. J., Jeffrey, L. C., Carson, M., Chen, Z. & Pickart, C. M. Structure of a diubiquitin conjugate and a model for interaction with ubiquitin conjugating enzyme (E2). J. Biol. Chem. 267, 16467–16471 (1992)

    CAS  PubMed  Google Scholar 

  37. Bremm, A., Freund, S. M. & Komander, D. Lys11-linked ubiquitin chains adopt compact conformations and are preferentially hydrolyzed by the deubiquitinase Cezanne. Nature Struct. Mol. Biol. 17, 939–947 (2010)

    Article  CAS  Google Scholar 

  38. Husnjak, K. et al. Proteasome subunit Rpn13 is a novel ubiquitin receptor. Nature 453, 481–488 (2008)

    Article  ADS  CAS  Google Scholar 

  39. Hanna, J. et al. Deubiquitinating enzyme Ubp6 functions noncatalytically to delay proteasomal degradation. Cell 127, 99–111 (2006)

    Article  CAS  Google Scholar 

  40. Prakash, S., Tian, L., Ratliff, K. S., Lehotzky, R. E. & Matouschek, A. An unstructured initiation site is required for efficient proteasome-mediated degradation. Nature Struct. Mol. Biol. 11, 830–837 (2004)

    Article  CAS  Google Scholar 

  41. Verma, R. et al. Proteasomal proteomics: identification of nucleotide-sensitive proteasome-interacting proteins by mass spectrometric analysis of affinity-purified proteasomes. Mol. Biol. Cell 11, 3425–3439 (2000)

    Article  CAS  Google Scholar 

  42. Leggett, D. S., Glickman, M. H. & Finley, D. Purification of proteasomes, proteasome subcomplexes, and proteasome-associated proteins from budding yeast. Methods Mol. Biol. 301, 57–70 (2005)

    CAS  PubMed  Google Scholar 

  43. Suloway, C. et al. Automated molecular microscopy: the new Leginon system. J. Struct. Biol. 151, 41–60 (2005)

    Article  CAS  Google Scholar 

  44. Lander, G. C. et al. Appion: an integrated, database-driven pipeline to facilitate EM image processing. J. Struct. Biol. 166, 95–102 (2009)

    Article  CAS  Google Scholar 

  45. Tang, G. et al. EMAN2: an extensible image processing suite for electron microscopy. J. Struct. Biol. 157, 38–46 (2007)

    Article  CAS  Google Scholar 

  46. Hohn, M. et al. SPARX, a new environment for Cryo-EM image processing. J. Struct. Biol. 157, 47–55 (2007)

    Article  CAS  Google Scholar 

  47. Goddard, T. D., Huang, C. C. & Ferrin, T. E. Visualizing density maps with UCSF Chimera. J. Struct. Biol. 157, 281–287 (2007)

    Article  CAS  Google Scholar 

  48. Sone, T., Saeki, Y., Toh-e, A. & Yokosawa, H. Sem1p is a novel subunit of the 26 S proteasome from Saccharomyces cerevisiae. J. Biol. Chem. 279, 28807–28816 (2004)

    Article  CAS  Google Scholar 

  49. Kim, H. C. & Huibregtse, J. M. Polyubiquitination by HECT E3s and the determinants of chain type specificity. Mol. Cell. Biol. 29, 3307–3318 (2009)

    Article  CAS  Google Scholar 

  50. Mallick, S. P., Carragher, B., Potter, C. S. & Kriegman, D. J. ACE: automated CTF estimation. Ultramicroscopy 104, 8–29 (2005)

    Article  CAS  Google Scholar 

  51. Mindell, J. A. & Grigorieff, N. Accurate determination of local defocus and specimen tilt in electron microscopy. J. Struct. Biol. 142, 334–347 (2003)

    Article  Google Scholar 

  52. Voss, N. R., Yoshioka, C. K., Radermacher, M., Potter, C. S. & Carragher, B. DoG Picker and TiltPicker: software tools to facilitate particle selection in single particle electron microscopy. J. Struct. Biol. 166, 205–213 (2009)

    Article  CAS  Google Scholar 

  53. Sorzano, C. O. et al. XMIPP: a new generation of an open-source image processing package for electron microscopy. J. Struct. Biol. 148, 194–204 (2004)

    Article  CAS  Google Scholar 

  54. van Heel, M., Harauz, G., Orlova, E. V., Schmidt, R. & Schatz, M. A new generation of the IMAGIC image processing system. J. Struct. Biol. 116, 17–24 (1996)

    Article  CAS  Google Scholar 

  55. Frank, J. et al. SPIDER and WEB: processing and visualization of images in 3D electron microscopy and related fields. J. Struct. Biol. 116, 190–199 (1996)

    Article  CAS  Google Scholar 

  56. Heymann, J. B. & Belnap, D. M. Bsoft: image processing and molecular modeling for electron microscopy. J. Struct. Biol. 157, 3–18 (2007)

    Article  CAS  Google Scholar 

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Acknowledgements

We thank the members of the Martin and Nogales labs for helpful discussions, and G. Cardone for help with local resolution calculations. G.C.L. acknowledges support from Damon Runyon Cancer Research Foundation, M.E.M. acknowledges support by the American Cancer Society grant 121453-PF-11-178-01-TBE, C.B. acknowledges support from the NSF Graduate Research Fellowship. This research was funded in part by the Searle Scholars Program (A.M.), start-up funds from the UC Berkeley MCB Department (A.M.), the NIH grant R01-GM094497-01A1 (A.M.), the Lawrence Berkeley National Laboratory (G.C.L.), and the Howard Hughes Medical Institute (E.N.). Some of the work presented here was conducted at the National Resource for Automated Molecular Microscopy, which is supported by the NIH through the NCRR P41 program (RR017573).

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Authors

Contributions

E.E., M.E.M. and C.B. designed, expressed and purified proteasome constructs, and performed biochemical experiments. G.C.L. performed the electron microscopy, processing and segmentation analysis. All authors contributed to experimental design, data analysis and manuscript preparation.

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Correspondence to Andreas Martin.

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The authors declare no competing financial interests.

Supplementary information

Supplementary Information

The file contains Supplementary Figures 1-12 with legends and Supplementary Table 1. (PDF 9249 kb)

Supplementary Movie 1

The movie shows the 3D reconstruction of the yeast 26S proteasome and the spatial arrangement of all subunits within its regulatory particle, including the ubiquitin receptors and the deubiquitinating enzyme. Docking of crystal structures from homologous proteins reveals a spiral stair case orientation of the six ATPase subunits within the base unfoldase and a horseshoe-shaped arrangement of PCI domains in the lid subcomplex. (MOV 27606 kb)

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Lander, G., Estrin, E., Matyskiela, M. et al. Complete subunit architecture of the proteasome regulatory particle. Nature 482, 186–191 (2012). https://doi.org/10.1038/nature10774

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