Phosphorylation-triggered CUEDC2 degradation promotes UV-induced G1 arrest through APC/C(Cdh1) regulation.
Proc Natl Acad Sci U S A 2013;
110:11017-22. [PMID:
23776205 DOI:
10.1073/pnas.1221009110]
[Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
DNA damage triggers cell cycle arrest to provide a time window for DNA repair. Failure of arrest could lead to genomic instability and tumorigenesis. DNA damage-induced G1 arrest is generally achieved by the accumulation of Cyclin-dependent kinase inhibitor 1 (p21). However, p21 is degraded and does not play a role in UV-induced G1 arrest. The mechanism of UV-induced G1 arrest thus remains elusive. Here, we have identified a critical role for CUE domain-containing protein 2 (CUEDC2) in this process. CUEDC2 binds to and inhibits anaphase-promoting complex/cyclosome-Cdh1 (APC/C(Cdh1)), a critical ubiquitin ligase in G1 phase, thereby stabilizing Cyclin A and promoting G1-S transition. In response to UV irradiation, CUEDC2 undergoes ERK1/2-dependent phosphorylation and ubiquitin-dependent degradation, leading to APC/C(Cdh1)-mediated Cyclin A destruction, Cyclin-dependent kinase 2 inactivation, and G1 arrest. A nonphosphorylatable CUEDC2 mutant is resistant to UV-induced degradation. Expression of this stable mutant effectively overrides UV-induced G1-S block. These results establish CUEDC2 as an APC/C(Cdh1) inhibitor and indicate that regulated CUEDC2 degradation is critical for UV-induced G1 arrest.
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