title: Nerve growth factor stimulation of the Ras-guanine nucleotide exchange factor and GAP activities.
abstract: The biological activity of Ras proteins is thought to be controlled by the guanine nucleotide exchange factor and the guanosine triphosphatase activating protein (GAP). Treatment of rat pheochromocytoma PC-12 cells with nerve growth factor (NGF) increased the amount of active Ras guanosine triphosphate complex and stimulated the activities of both the guanine nucleotide exchange factor and GAP. In PC-12 cells that overexpressed the tyrosine kinase encoded by the trk proto-oncogene (a component of the high-affinity NGF receptor), the NGF-induced activation of the regulatory proteins was potentiated. These results suggest that the NGF receptor system enhances the activities of both the guanine nucleotide exchange factor and GAP and that the activation of Ras might be controlled by the balance in activity between these two regulatory proteins.
authors.affiliation: Biological Carcinogenesis and Development Program, Program Resources, Inc./DynCorp, Frederick, MD 21702.
authors.forename: B Q
authors.initials: BQ
authors.lastname: Li
authors.forename: D
authors.initials: D
authors.lastname: Kaplan
authors.forename: H F
authors.initials: HF
authors.lastname: Kung
authors.forename: T
authors.initials: T
authors.lastname: Kamata
mesh_terms: D000818:Animals; D002852:Chromatography, Ion Exchange; D020690:GTPase-Activating Proteins; D020662:Guanine Nucleotide Exchange Factors; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology; D006153:Guanosine Diphosphate / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism; D007700:Kinetics; D008970:Molecular Weight; D009414:Nerve Growth Factors / Q000494:pharmacology*; D016716:PC12 Cells; D010710:Phosphates / Q000378:metabolism; D011506:Proteins / Q000302:isolation & purification / Q000378:metabolism*; D013347:Subcellular Fractions / Q000378:metabolism; D020703:ras GTPase-Activating Proteins; D020663:ras Guanine Nucleotide Exchange Factors
chemical_list: D020690:GTPase-Activating Proteins; D020662:Guanine Nucleotide Exchange Factors; D009414:Nerve Growth Factors; D010710:Phosphates; D011506:Proteins; D020703:ras GTPase-Activating Proteins; D020663:ras Guanine Nucleotide Exchange Factors; D006153:Guanosine Diphosphate; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate