Modulation of cellular phorbol ester binding and/or protein kinase C activity by human placental fractions.
We describe two factors in human placenta that modulate the interaction of phorbol ester tumor promoters with cell membranes or with protein kinase C. One, phorbol ester binding inhibitory factor, can inhibit binding of [3H]phorbol-12,13-dibutyrate to cultured cells or to a membrane fraction but does not inhibit its binding to a homogeneous C kinase preparation (phorbol ester binding sites). The other, C kinase activating factor, stimulates C kinase activity in a calcium-dependent manner. We separated these two biochemical activities from a crude human placental fraction by gel filtration.
Hamel
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International Agency for Research on Cancer, Lyon, France.
Tayot
J L
JL
Yamasaki
H
H
D000818:Animals; D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins; D002460:Cell Line; D002850:Chromatography, Gel; D004347:Drug Interactions; D004789:Enzyme Activation / Q000187:drug effects; D005260:Female; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D015240:Phorbol 12,13-Dibutyrate; D010703:Phorbol Esters / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010924:Placental Extracts / Q000302:isolation & purification / Q000494:pharmacology*; D011247:Pregnancy; D011493:Protein Kinase C / Q000378:metabolism*; D011955:Receptors, Drug / Q000187:drug effects*; D012995:Solubility
D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins; D010703:Phorbol Esters; D010924:Placental Extracts; D011955:Receptors, Drug; C083141:phorbol ester binding protein; C027776:phorbol ester receptor; D015240:Phorbol 12,13-Dibutyrate; D011493:Protein Kinase C