The protein kinase p90 rsk as an essential mediator of cytostatic factor activity.
Persistent activation of p42 mitogen-activated protein kinase (p42 MAPK) during mitosis induces a "cytostatic factor" arrest, the arrest responsible for preventing the parthenogenetic activation of unfertilized eggs. The protein kinase p90 Rsk is a substrate of p42 MAPK; thus, the role of p90 Rsk in p42 MAPK-induced mitotic arrest was examined. Xenopus laevis egg extracts immunodepleted of Rsk lost their capacity to undergo mitotic arrest in response to activation of the Mos-MEK-1-p42 MAPK cascade of protein kinases. Replenishing Rsk-depleted extracts with catalytically competent Rsk protein restored the ability of the extracts to undergo mitotic arrest. Rsk appears to be essential for cytostatic factor arrest.
Bhatt
R R
RR
Department of Molecular Pharmacology, Stanford University School of Medicine, Stanford, CA 94305-5332, USA.
Ferrell
J E
JE
D000818:Animals; D016203:CDC2 Protein Kinase / Q000378:metabolism; D002457:Cell Extracts; D004789:Enzyme Activation; D048369:MAP Kinase Kinase 1; D020935:MAP Kinase Signaling System; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism; D008938:Mitosis; D008969:Molecular Sequence Data; D010063:Ovum / Q000166:cytology* / Q000201:enzymology; D017346:Protein Serine-Threonine Kinases; D017231:Proto-Oncogene Proteins c-mos / Q000378:metabolism* / Q000494:pharmacology; D019893:Ribosomal Protein S6 Kinases / Q000378:metabolism*; D014982:Xenopus laevis
D002457:Cell Extracts; D017346:Protein Serine-Threonine Kinases; D017231:Proto-Oncogene Proteins c-mos; D019893:Ribosomal Protein S6 Kinases; D016203:CDC2 Protein Kinase; D019950:Mitogen-Activated Protein Kinase 1; D048369:MAP Kinase Kinase 1; D020929:Mitogen-Activated Protein Kinase Kinases