title: Protein tyrosine kinase Wee1B is essential for metaphase II exit in mouse oocytes.
abstract: Waves of cyclin synthesis and degradation regulate the activity of Cdc2 protein kinase during the cell cycle. Cdc2 inactivation by Wee1B-mediated phosphorylation is necessary for arrest of the oocyte at G2-prophase, but it is unclear whether this regulation functions later during the metaphase-to-anaphase transition. We show that reactivation of a Wee1B pathway triggers the decrease in Cdc2 activity during egg activation. When Wee1B is down-regulated, oocytes fail to form a pronucleus in response to Ca(2+) signals. Calcium-calmodulin-dependent kinase II (CaMKII) activates Wee1B, and CaMKII-driven exit from metaphase II is inhibited by Wee1B down-regulation, demonstrating that exit from metaphase requires not only a proteolytic degradation of cyclin B but also the inhibitory phosphorylation of Cdc2 by Wee1B.
authors: Center for Reproductive Sciences, Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco, CA 94143-0556, USA.
authors: Jeong Su
authors: JS
authors: Oh
authors: Andrej
authors: A
authors: Susor
authors: Marco
authors: M
authors: Conti
mesh_terms: D000818:Animals; D016203:CDC2 Protein Kinase / Q000037:antagonists & inhibitors / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2 / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D019926:Cyclin B / Q000235:genetics / Q000378:metabolism; D015536:Down-Regulation; D005260:Female; D055785:Gene Knockdown Techniques; D016200:Maturation-Promoting Factor / Q000378:metabolism; D008540:Meiosis; D008677:Metaphase; D051379:Mice; D008810:Mice, Inbred C57BL; D009865:Oocytes / Q000502:physiology*; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D018797:Cell Cycle Proteins; D019926:Cyclin B; D012333:RNA, Messenger; C509498:Wee1B protein, mouse; D011505:Protein-Tyrosine Kinases; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D016203:CDC2 Protein Kinase; D016200:Maturation-Promoting Factor; D002118:Calcium