CaMKII and polo-like kinase 1 sequentially phosphorylate the cytostatic factor Emi2/XErp1 to trigger its destruction and meiotic exit.

ABSTRACT: In vertebrate meiosis, unfertilized eggs are arrested in metaphase II by cytostatic factor (CSF), which is required to maintain mitotic cyclin-dependent kinase activity. Fertilization triggers a transient increase in cytosolic free Ca(2+), which leads to CSF inactivation and ubiquitin-dependent cyclin destruction through the anaphase promoting complex or cyclosome (APC/C). The Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) and the Polo-like kinase Plx1 are essential factors for Ca(2+)-induced meiotic exit, but the critical targets of these kinases were unknown. The APC/C inhibitor Emi2 or XErp1 has recently been characterized as a pivotal CSF component, required to maintain metaphase II arrest and rapidly destroyed in response to Ca(2+) signaling through phosphorylation by Plx1 and

SUBMITTER: Hansen DV 

PROVIDER: S-EPMC1325965 | biostudies-literature | 2006 Jan

REPOSITORIES: biostudies-literature