The G2-to-M Transition Is Ensured by a Dual Mechanism that Protects Cyclin B from Degradation by Cdc20-Activated APC/C.

ABSTRACT: In the eukaryotic cell cycle, a threshold level of cyclin B accumulation triggers the G2-to-M transition, and subsequent cyclin B destruction triggers mitotic exit. The anaphase-promoting complex/cyclosome (APC/C) is the E3 ubiquitin ligase that, together with its co-activator Cdc20, targets cyclin B for destruction during mitotic exit. Here, we show that two pathways act in concert to protect cyclin B from Cdc20-activated APC/C in G2, in order to enable cyclin B accumulation and the G2-to-M transition. The first pathway involves the Mad1-Mad2 spindle checkpoint complex, acting in a distinct manner from checkpoint signaling after mitotic entry but employing a common molecular mechanism-the promotion of Mad2-Cdc20 complex formation. The second pathway involves cyclin-dependent kinase phosph

SUBMITTER: Lara-Gonzalez P 

PROVIDER: S-EPMC7778526 | biostudies-literature | 2019 Nov

REPOSITORIES: biostudies-literature