Protein phosphorylation in the corpus luteum.
Soluble luteal extracts were incubated with putative second messengers or regulators of protein kinases in the presence of [gamma-32P]ATP, and proteins were separated by SDS-PAGE. There was a novel phosphorylation of a protein of Mr 80,000 which was stimulated by phospholipid and 1,2-diacylglycerol but, unlike classical C-kinase phosphorylating activity, was increased by EGTA and reduced by Ca2+. This phospholipid/diolein-stimulated phosphorylation of a Mr 80,000 protein was detectable in rat and pig luteal extracts and was enhanced 2-fold in rabbit CL by administration of oestradiol-17 beta in vivo. These results suggest that the luteotrophic functions of oestradiol in rabbit CL are mediated in part by regulating either the kinase and/or the Mr 80,000 substrate.
Maizels
E T
ET
Department of Molecular Biology, Northwestern University Medical School, Chicago, IL 60611.
Ekstrom
R C
RC
Miller
J B
JB
Hunzicker-Dunn
M
M
D000818:Animals; D001345:Autoradiography; D003338:Corpus Luteum / Q000187:drug effects / Q000378:metabolism*; D003340:Corpus Luteum Maintenance; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D010766:Phosphorylation; D011247:Pregnancy; D011493:Protein Kinase C / Q000378:metabolism; D011506:Proteins / Q000378:metabolism*; D011817:Rabbits; D051381:Rats; D011919:Rats, Inbred Strains; D013552:Swine
D011506:Proteins; D004958:Estradiol; D011493:Protein Kinase C