Two different modes of cyclin Clb2 proteolysis during mitosis in Saccharomyces cerevisiae

FEBS Letters

Braus, Gerhard H¹  Irniger, Stefan¹  Bäumer, Matthias¹ 

[1] Institute of Microbiology and Genetics, Georg-August-University, Grisebachstrasse 8, D-37077 Göttingen, Germany

关键词: Anaphase-promoting complex;    Cyclin degradation;    Cdh1;    Cdc15;    Mitotic exit;    Ubiquitin-dependent proteolysis;    APC/C;    anaphase-promoting complex/cyclosome;    CDK;    cyclin-dependent kinase;    OD;    optical density;   

DOI  :  10.1016/S0014-5793(00)01208-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Sister chromatid separation and mitotic exit are triggered by the anaphase-promoting complex (APC/C) which is a multi-subunit ubiquitin ligase required for proteolytic degradation of various target proteins. Cdc20 and Cdh1 are substrate-specific activators of the APC/C. It was previously proposed that Cdh1 is essential for proteolysis of the yeast mitotic cyclin Clb2. We show that Clb2 proteolysis is triggered by two different modes during mitosis. A fraction of Clb2 is degraded during anaphase in the absence of Cdh1. However, a second fraction of Clb2 remains stable during anaphase and is degraded in a Cdh1-dependent manner as cells exit from mitosis. Most of cyclin Clb3 is degraded independently of Cdh1. Our data imply that degradation of mitotic cyclins is initiated by a Cdh1-independent mechanism.

【 授权许可】

Unknown