Click here to close Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly. We suggest using a current version of Chrome, FireFox, or Safari.
XB-ART-45455
EMBO J 2012 Aug 01;3115:3351-62. doi: 10.1038/emboj.2012.168.
Show Gene links Show Anatomy links

Dephosphorylation of Cdc20 is required for its C-box-dependent activation of the APC/C.

Labit H , Fujimitsu K , Bayin NS , Takaki T , Gannon J , Yamano H .


???displayArticle.abstract???
The anaphase-promoting complex/cyclosome (APC/C) ubiquitin ligase is tightly regulated to ensure programmed proteolysis in cells. The activity of the APC/C is positively controlled by cyclin-dependent kinase (CDK), but a second level of control must also exist because phosphorylation inactivates Cdc20, a mitotic APC/C co-activator. How Cdc20 is dephosphorylated specifically, when CDK is high, has remained unexplained. Here, we show that phosphatases are crucial to activate the APC/C. Cdc20 is phosphorylated at six conserved residues (S50/T64/T68/T79/S114/S165) by CDK in Xenopus egg extracts. When all the threonine residues are phosphorylated, Cdc20 binding to and activation of the APC/C are inhibited. Their dephosphorylation is regulated depending on the sites and protein phosphatase 2A, active in mitosis, is essential to dephosphorylate the threonine residues and activate the APC/C. Consistently, most of the Cdc20 bound to the APC/C in anaphase evades phosphorylation at T79. Furthermore, we show that the 'activation domain' of Cdc20 associates with the Apc6 and Apc8 core subunits. Our data suggest that dephosphorylation of Cdc20 is required for its loading and activation of the APC/C ubiquitin ligase.

???displayArticle.pubmedLink??? 22713866
???displayArticle.pmcLink??? PMC3411074
???displayArticle.link??? EMBO J
???displayArticle.grants??? [+]

Species referenced: Xenopus laevis
Genes referenced: cdc20

References [+] :
Barford, Structure, function and mechanism of the anaphase promoting complex (APC/C). 2011, Pubmed