The regulatory effect of nucleoside diphosphate kinase on G-protein and G-protein mediated phospholipase C.
The effect of nucleoside diphosphate kinase (NDPK) on the activity of guanine nucleotide regulatory protein (G-protein) mediated phospholipase C (PLC) and on the [35S] GTPT tau S binding of G-protein was investigated in this work in order to demonstrate the mechanism behind the regulation of G-protein and its effector PLC by NDPK. The stimulation of PLC in turkey erythrocyte membrane by both GTP and GTP tau S indicated that the PLC stimulation was mediated by G-protein. NDPK alone stimulated PLC activity, as well as the stimulation in the presence of GTP and GDP, in a dose-dependent manner. However, NDPK inhibited GTP tau S-stimulated PLC. Furthermore, NDPK inhibited [35S]GTP tau S binding of purified Gi-protein in a non-competitive manner. A hypothesis implying an important role of direct interaction of G-protein and NDPK in the regulation of their functions is suggested and discussed.
Zhang
D
D
Department of Pharmacology, Institute of Basic Medical Sciences, CAMS, Beijing.
Chang
K
K
D000818:Animals; D004910:Erythrocyte Membrane / Q000201:enzymology; D019204:GTP-Binding Proteins / Q000378:metabolism*; D006150:Guanine Nucleotides / Q000494:pharmacology; D009701:Nucleoside-Diphosphate Kinase / Q000494:pharmacology*; D014421:Turkey; D010738:Type C Phospholipases / Q000378:metabolism*
D006150:Guanine Nucleotides; D009701:Nucleoside-Diphosphate Kinase; D010738:Type C Phospholipases; D019204:GTP-Binding Proteins