4. Conclusions

  • We have identified the Dmp1?Dmp2 (human PAC3-PAC4 orthologs) complex as a proteasome specific assembling chaperone (PAC).
  • We have determined the crystal structures of the Dmp1-Dmp2 and the Dmp1-Dmp2-α5 proteasomal subunit complex.
  • The structures of the Dmp1-Dmp2 and the Dmp1-Dmp2-α5 complex revealed how this chaperone functions in proteasome assmbly and why it dissociates from proteasome precursors (assembling intermediates) before the α-ring are assembled.
  • We unclosed the mechanism of β-ring formation on α-rings.

References

  • Hirano, Y. et al., A heterodimeric complex that promotes the assembly of mammalian 20S proteasomes, Nature 437, 1381-1385 (2005)
  • Hirano, Y. et al., Cooperation of multiple chaperones required for the assembly of mammalian 20S proteasomes, Mol. Cell 24, 977-984 (2006)
  • Yashiroda, H. et al., Crystal structure of a chaperone complex that contributes to the assembly of yeast 20S proteasomes, Nature Struct. Mol. Biol. 15, 228 - 236 (2008)
  • Hirano, Y. et al., Dissecting b-ring assembly pathway of the mammalian 20S proteasome, EMBO J. 27, 2204- 2213 (2008)
  • Murata et al., Molecular mechanisms of proteasome assembly, Nature Rev. Mol. Cell Biol. in press
Conclusions