Protein kinase C translocates from cytosol to membrane upon hormone activation: effects of thyrotropin-releasing hormone in GH3 cells.
The subcellular distribution of protein kinase C (PK C) was examined in thyrotropin-releasing hormone (TRH)--responsive GH3 pituitary cells. TRH treatment, which is known to stimulate polyphosphoinositide turnover and diacylglycerol generation, resulted in a rapid (less than or equal to 15 sec) and transient redistribution of the enzyme from cytosol to membrane fraction. Other agents which either stimulate PK C directly (1-oleoyl-2-acetyl-sn-glycerol and 12-O-tetradecanoyl phorbol-13-acetate) or elevate cellular diglyceride levels (phospholipase C) also promoted a redistribution of the enzyme from cytosol to membrane. These results provide evidence for the concept that cell-surface receptor-mediated phosphoinositide breakdown activates PK C. It appears that translocation of PK C to the membrane is an early step in the cellular activation of this enzyme.
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D000818:Animals; D001464:Barium / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects; D002460:Cell Line; D002462:Cell Membrane / Q000201:enzymology*; D003600:Cytosol / Q000201:enzymology*; D010911:Pituitary Neoplasms / Q000201:enzymology; D011188:Potassium / Q000494:pharmacology; D011493:Protein Kinase C; D011494:Protein Kinases / Q000378:metabolism*; D051381:Rats; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology*; D010738:Type C Phospholipases / Q000378:metabolism
D001464:Barium; D013973:Thyrotropin-Releasing Hormone; D011494:Protein Kinases; D011493:Protein Kinase C; D010738:Type C Phospholipases; D013755:Tetradecanoylphorbol Acetate; D011188:Potassium