title: The Rap1A protein enhances protein kinase C activity in vitro.
abstract: The low molecular weight G protein Rap1A constitutes a major fraction of the GTP-binding proteins found in the plasma membrane and specific granules of the neutrophil; however, the function of Rap1A in neutrophil responses remains unclear. Protein kinase C assays were performed to examine the effects of Rap1A on protein kinase C activity. In the presence of recombinant Rap1A, the phosphorylation of protein kinase C substrates was significantly enhanced. The effect of the Rap1A on protein kinase C activity was concentration-dependent and specific. The low molecular weight G protein Rac 2 had no effect on protein kinase C activity. These results suggest that Rap1A may interact with protein kinases and regulate signal transduction.
authors.affiliation: Department of Pathology, University of Connecticut Health Center, Farmington 06030.
authors.forename: M E
authors.initials: ME
authors.lastname: Labadia
authors.forename: G M
authors.initials: GM
authors.lastname: Bokoch
authors.forename: C K
authors.initials: CK
authors.lastname: Huang
mesh_terms: D001483:Base Sequence; D019204:GTP-Binding Proteins / Q000378:metabolism*; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology; D006153:Guanosine Diphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D008969:Molecular Sequence Data; D009252:NADPH Dehydrogenase / Q000378:metabolism; D019255:NADPH Oxidases; D009504:Neutrophils; D010446:Peptide Fragments / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism; D011493:Protein Kinase C / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D015398:Signal Transduction; D013379:Substrate Specificity; D013873:Thionucleotides / Q000494:pharmacology; D020744:rac GTP-Binding Proteins; D020668:rap GTP-Binding Proteins
chemical_list: D010446:Peptide Fragments; D010750:Phosphoproteins; D011994:Recombinant Proteins; D013873:Thionucleotides; D006153:Guanosine Diphosphate; D016244:Guanosine 5'-O-(3-Thiotriphosphate); C023427:guanosine 5'-O-(2-thiodiphosphate); D019255:NADPH Oxidases; C060505:neutrophil cytosolic factor 1; D009252:NADPH Dehydrogenase; D011493:Protein Kinase C; D019204:GTP-Binding Proteins; D020744:rac GTP-Binding Proteins; D020668:rap GTP-Binding Proteins