First Author | Xu X | Year | 2008 |
Journal | Mol Cell | Volume | 30 |
Issue | 4 | Pages | 403-14 |
PubMed ID | 18498745 | Mgi Jnum | J:137062 |
Mgi Id | MGI:3797700 | Doi | 10.1016/j.molcel.2008.03.009 |
Citation | Xu X, et al. (2008) The CUL7 E3 ubiquitin ligase targets insulin receptor substrate 1 for ubiquitin-dependent degradation. Mol Cell 30(4):403-14 |
abstractText | Recent genetic studies have documented a pivotal growth-regulatory role played by the Cullin 7 (CUL7) E3 ubiquitin ligase complex containing the Fbw8-substrate-targeting subunit, Skp1, and the ROC1 RING finger protein. In this report, we identified insulin receptor substrate 1 (IRS-1), a critical mediator of the insulin/insulin-like growth factor 1 signaling, as a proteolytic target of the CUL7 E3 ligase in a manner that depends on mammalian target of rapamycin and the p70 S6 kinase activities. Interestingly, while embryonic fibroblasts of Cul7-/- mice were found to accumulate IRS-1 and exhibit increased activation of IRS-1's downstream Akt and MEK/ERK pathways, these null cells grew poorly and displayed phenotypes reminiscent of those associated with oncogene-induced senescence. Taken together, our findings demonstrate a key role for the CUL7 E3 in targeting IRS-1 for degradation, a process that may contribute to the regulation of cellular senescence. |