CAK, the p34cdc2 activating kinase, contains a protein identical or closely related to p40MO15.

摘要: Abstract The mitotic inducer p34cdc2 requires association with a cyclin and phosphorylation on Thr161 for its activity as protein kinase. CAK, the activating kinase, was previously identified an enzyme necessary this phosphorylation. We confirm here that CAK is kinase describe purification over 13,000-fold from Xenopus egg extracts. further show contains identical or closely related to MO15 gene: p40MO15 copurifies antiserum specifically depletes cAK activity. appears be only in extracts can activate complexes of either p33cdk2, A B. The sequence similarity between p34cdc2, approximately 200 kDa size suggest may itself regulated by subunit phosphorylations.