Proteasome proteolysis

Two ubiquitin ligase complexes (orange), SCF and APC, polyubiquitinate specific substrates including S-phase inhibitors (step B), securin (step ), and mitotic cyclins (step El), marking these substrates for degradation by proteasomes. Proteolysis of the S-phase inhibitor activates S-phase cyclin-CDK complexes. 

In addition to protein proteolysis during mitosis, ubiquitin-mediated protein degradation ( ubiquitin/ proteasome) is also required at the G1 to S transition... 

The human genome contains more than 90 different DUBs. Besides cleaving ubiquitin from distinct substrates, DUBs are also responsible for the recycling of free ubiquitin from ubiquitin chains and processing of ubiquitin- or ubiquitin like precursor proteins. Certain DUBs are also associated with the proteasome in order to detach ubiquitin chains before proteolysis. 

J. A., Saidowsky, j., Eschee, C., and Wole, D. H. Proteinase yscE, the yeast proteasome/multicatalytic-multifunc-tional proteinase mutants unravel its function in stress induced proteolysis and uncover its necessity for cell survival. EMBO J. 1991, 30, 555-62. 

Guterman, a. and Glickman, M. H. Complementary roles for Rpnll and Ubp6 in deubiquitination and proteolysis by the proteasome, J Biol Chem, 2004, 279, 1729-38. 

The 26S proteasome also degrades non-ubiquitylated proteins [71]. The short-lived enzyme ornithine decarboxylase (ODC) and the cell-cycle regulator p21Cip provide well documented examples of ubiquitin-independent proteolysis by the 26S en-... 

WojciK, C., Yano, M., and DeMartino, G. N. RNA interference of valosin-containing protein (VCP/ p97) reveals multiple cellular roles linked to ubiquitin/ proteasome-dependent proteolysis. J Cell Sd 2004, 117, 281-92. 

Tanahashi, N. et al. Hybrid proteasomes. Induction by interferon-gamma and contribution to ATP-dependent proteolysis. J. Biol. Chem. 2000, 275, 14336-14345. 

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