Luteinizing hormone-releasing hormone-signal transduction and stathmin phosphorylation in the gonadotrope alphaT3-1 cell line.
We have investigated the effects of GnRH (LHRH) and of the protein kinase C (PKC) activator 12-O-tetradecanoylphorbol-13-acetate on stathmin phosphorylation in the gonadotrope alphaT3-1 cell line. Stathmin expression and its phosphorylation were maximal during the exponential phase of cell growth. LHRH stimulated stathmin phosphorylation through a specific receptor in a dose- and time-dependent manner, and TPA induced a similar extensive stathmin phosphorylation. Their effects were inhibited either in PKC-depleted alphaT3-1 cells, or by the PKC inhibitor staurosporine. In the context of the known implication of PKC in LHRH-induced signal transduction, our results show that stathmin phosphorylation is involved in LHRH transduction, either as a result of direct activation of specific PKC isoforms or through a pathway involving kinases downstream to PKC activation.
Drouva
S V
SV
CNRS UMR 6544, Université de la Méditerranée, Faculté de Médecine Nord, Bd Pierre Dramard, Marseille, France.
Poulin
B
B
Manceau
V
V
Sobel
A
A
D000818:Animals; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology*; D051379:Mice; D008822:Mice, Transgenic; D008868:Microtubule Proteins; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D010902:Pituitary Gland / Q000378:metabolism*; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism; D015398:Signal Transduction; D050777:Stathmin; D019311:Staurosporine / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D004791:Enzyme Inhibitors; D008868:Microtubule Proteins; D010750:Phosphoproteins; D050777:Stathmin; C493994:Stmn1 protein, mouse; D007987:Gonadotropin-Releasing Hormone; D011493:Protein Kinase C; D019311:Staurosporine; D013755:Tetradecanoylphorbol Acetate