First Author | Amador V | Year | 2007 |
Journal | Mol Cell | Volume | 27 |
Issue | 3 | Pages | 462-73 |
PubMed ID | 17679094 | Mgi Jnum | J:134816 |
Mgi Id | MGI:3789835 | Doi | 10.1016/j.molcel.2007.06.013 |
Citation | Amador V, et al. (2007) APC/C(Cdc20) controls the ubiquitin-mediated degradation of p21 in prometaphase. Mol Cell 27(3):462-73 |
abstractText | During the G1/S transition, p21 proteolysis is mediated by Skp2; however, p21 reaccumulates in G2 and is degraded again in prometaphase. How p21 degradation is controlled in mitosis remains unexplored. We found that Cdc20 (an activator of the ubiquitin ligase APC/C) binds p21 in cultured cells and identified a D box motif in p21 necessary for APC/C(Cdc20)-mediated ubiquitylation of p21. Overexpression of Cdc20 or Skp2 destabilized wild-type p21; however, only Skp2, but not Cdc20, was able to destabilize a p21(D box) mutant. Silencing of Cdc20 induced an accumulation of p21, increased the fraction of p21 bound to Cdk1, and inhibited Cdk1 activity in p21(+/+) prometaphase cells, but not in p21(-/-) cells. Thus, in prometaphase Cdc20 positively regulates Cdk1 by mediating the degradation of p21. We propose that the APC/C(Cdc20)-mediated degradation of p21 contributes to the full activation of Cdk1 necessary for mitotic events and prevents mitotic slippage during spindle checkpoint activation. |