[Effect of LHRH on the synthesis and phosphorylation of proteins in gonadotropic cells].
Protein secretion by cultured pituitary cells from 14 day-old female rats was estimated using [35S]-méthionine incorporation, electrophoresis and autoradiography. Stimulation by LHRH promoted biosynthesis and fast release of a protein of apparent molecular weight 87,000 daltons and pI 4.6. Gonadotrophs enriched by centrifugal elutriation were particularly rich in this polypeptide which was thus called GP-87 (Gonadotrope polypeptide). Cells were then cultured with [32P]-orthophosphate and proteins were analyzed. Our first results tend to show that GP-87 is phosphorylated, at least in the cells. We suggest that this specific protein, the secretion of which is correlated with LH release, participates to the response mechanisms of gonadotrope cells stimulated by LHRH.
D000818:Animals; D001345:Autoradiography; D002864:Chromogranins; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology*; D007120:Immunochemistry; D066298:In Vitro Techniques; D008970:Molecular Weight; D010766:Phosphorylation; D010903:Pituitary Gland, Anterior / Q000378:metabolism*; D014176:Protein Biosynthesis; D011506:Proteins; D051381:Rats
D002864:Chromogranins; D011506:Proteins; D007987:Gonadotropin-Releasing Hormone
Action de la LHRH sur la synthèse et la phosphorylation de protéines dans les cellules gonadotropes.