Mitosis-specific monoclonal antibody MPM-2 inhibits Xenopus oocyte maturation and depletes maturation-promoting activity.
MPM-2, a monoclonal antibody specific for cells in mitosis, recognizes a family of proteins that share a common phosphorylated epitope. In this study we have shown that during the maturation of Xenopus laevis oocytes induced by progesterone, phosphorylation of MPM-2 antigens coincided with the appearance of MPF activity. When MPM-2 (0.7-1.4 micrograms per oocyte) was injected into oocytes prior to progesterone stimulation, MPF activity failed to appear and induction of maturation was inhibited as judged by both germinal-vesicle breakdown and white-spot formation. Further, MPM-2 was able to neutralize as well as immunodeplete MPF activity from mitotic HeLa cell and mature oocyte extracts. These results suggest that MPM-2 recognizes either MPF itself or a protein(s) that regulates MPF activity and that the kinase that phosphorylates MPM-2 antigens may be a key component in the regulation of M-phase induction.
Kuang
J
J
Department of Medical Oncology, University of Texas M. D. Anderson Cancer Center, Houston 77030.
Zhao
J
J
Wright
D A
DA
Saunders
G F
GF
Rao
P N
PN
D000818:Animals; D000911:Antibodies, Monoclonal / Q000302:isolation & purification; D000936:Antigen-Antibody Complex; D005260:Female; D006133:Growth Substances / Q000302:isolation & purification* / Q000494:pharmacology; D006367:HeLa Cells / Q000166:cytology; D006801:Humans; D007700:Kinetics; D016200:Maturation-Promoting Factor; D008938:Mitosis; D009865:Oocytes / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D014982:Xenopus laevis
D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D006133:Growth Substances; D016200:Maturation-Promoting Factor