First Author | Chen X | Year | 2007 |
Journal | Mol Cell | Volume | 26 |
Issue | 6 | Pages | 843-52 |
PubMed ID | 17588519 | Mgi Jnum | J:134921 |
Mgi Id | MGI:3790047 | Doi | 10.1016/j.molcel.2007.05.022 |
Citation | Chen X, et al. (2007) Ubiquitin-independent degradation of cell-cycle inhibitors by the REGgamma proteasome. Mol Cell 26(6):843-52 |
abstractText | The cell-cycle regulator p21(Cip1) is degraded by proteasomes independently of ubiquitination. We now show that degradation of p21 in vivo does not require the 19S proteasome lid, which contains the ubiquitin-binding subunit. Instead, the major proteasomal pathway for p21 degradation involves an alternative proteasome lid, the REGgamma complex. REGgamma binds to p21 in vivo, and deletion of p21's REGgamma-binding site greatly extends its half-life. Knockdown of REGgamma by RNA interference stabilizes p21, p21 has a significantly extended half-life in REGgamma(-/-) murine embryonic fibroblasts, and the p21 abundance is elevated in REGgamma(-/-) mice. The role of REGgamma in cell-cycle regulation may extend beyond p21 regulation, because p16(INK4A) and p19(Arf) also bind to REGgamma and are stabilized in REGgamma-deficient cells. |