Epidermal growth factor increases the labeling of phosphatidylinositol 3,4-bisphosphate in MA-10 Leydig tumor cells.
Previous studies from this laboratory have shown that mouse epidermal growth factor (mEGF) modulates the hormonal responsiveness of MA-10 Leydig tumor cells without affecting cell multiplication. In an attempt to characterize the intracellular signaling systems activated by mEGF in this cell type, we examined its effects on the labeling of phosphatidylinositols in cells that had been preincubated with different radioactive precursors. Here we report that exposure of MA-10 cells to mEGF, but not other ligands that affect their differentiated function, results in an increase in the labeling of an unusual phosphatidylinositol that does not appear to be present in unstimulated cells. This phosphatidylinositol has been identified as phosphatidylinositol 3,4-bisphosphate.
Pignataro
O P
OP
Population Council, New York, New York 10021.
Ascoli
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M
D000818:Animals; D001127:Arginine Vasopressin / Q000494:pharmacology; D002460:Cell Line; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D066298:In Vitro Techniques; D007984:Leydig Cell Tumor / Q000378:metabolism*; D051379:Mice; D010716:Phosphatidylinositols / Q000378:metabolism*; D051381:Rats
D006063:Chorionic Gonadotropin; D010716:Phosphatidylinositols; D001127:Arginine Vasopressin; D004815:Epidermal Growth Factor