Inhibition of APC-mediated proteolysis by the meiosis-specific protein kinase Ime2

• DOI: 10.1073/pnas.072385099
• Publication Date: 2002-07-26T14:37:36Z
• Authors: Melanie Bolte; Patrick Steigemann; Gerhard H. Braus; Stefan Irniger
• Keywords: Anaphase-promoting complex; Proteolysis; Cyclin B1; Securin; CDC20; Cyclin B

Proteolysis triggered by the anaphase-promoting complex (APC) is needed for sister chromatid separation and exit from mitosis. APC a ubiquitin ligase whose activity tightly controlled during cell cycle. To identify factors involved in regulation of APC-mediated proteolysis, Saccharomyces cerevisiae GAL-cDNA library was screened genes overexpression prevented degradation an target protein, mitotic cyclin Clb2. Genes encoding G 1 , S, cyclins were identified, consistent with previous data showing that cyclin-dependent kinase Cdk1 associated different key factor inhibiting Cdh1 late-G phase until In addition, meiosis-specific protein Ime2 identified as negative regulator proteolysis. Ectopic expression IME2 arrested cells inhibited other substrates. resulted phosphorylation cells, indicating regulate similar manner. The cycling bud formation caused to arrest We show further itself unstable proteolysis occurs independently SCF (Skp1/Cdc53/F-box) ligases. Our findings suggest represents unstable, .