The mechanism of CSF arrest in vertebrate oocytes.
A cytoplasmic activity in mature oocytes responsible for second meiotic metaphase arrest was identified over 30 years ago in amphibian oocytes. In Xenopus oocytes cytostatic factor (CSF) activity is initiated by the progesterone-dependent synthesis of Mos, a MAPK kinase kinase that activates the MAPK pathway. CSF arrest is mediated by a sole MAPK target, the protein kinase p90(Rsk). Rsk phosphorylates and activates the Bub1 protein kinase, which may cause metaphase arrest due to inhibition of the anaphase-promoting complex (APC) by a conserved mechanism defined genetically in yeast and mammalian cells. CSF arrest in vertebrate oocytes by p90(Rsk) provides a link between the MAPK pathway and the spindle assembly checkpoint in the cell cycle.
Maller
James L
JL
The Howard Hughes Medical Institute and Department of Pharmacology, University of Colorado School of Medicine, 4200 E. 9th Avenue, Box C236, Denver, CO 80262, USA. jim.maller@uchsc.edu
Schwab
Markus S
MS
Gross
Stefan D
SD
Taieb
Frédéric E
FE
Roberts
B Tibor
BT
Tunquist
Brian J
BJ
D000818:Animals; D002453:Cell Cycle / Q000502:physiology; D005260:Female; D006801:Humans; D020935:MAP Kinase Signaling System / Q000502:physiology; D008540:Meiosis; D009865:Oocytes / Q000166:cytology* / Q000378:metabolism; D017231:Proto-Oncogene Proteins c-mos / Q000502:physiology*; D014714:Vertebrates / Q000502:physiology*
D017231:Proto-Oncogene Proteins c-mos