Modulation of adenylate cyclase activity by Ca2+, phospholipid-dependent protein kinase in rat brain striatum.
The effects of purified Ca2+, phospholipid-dependent protein kinase (C-kinase) were studied on adenylate cyclase activity from rat brain striatum. C-kinase treatment of the membranes stimulated adenylate cyclase activity, the maximal stimulation between 50-80% was observed at 3.5 U/ml, whereas the catalytic subunit of cAMP dependent protein kinase did not show any effect on enzyme activity. The inclusion of Ca2+ and phosphatidyl serine did not augment the percent stimulation of adenylate cyclase by C-kinase, however EGTA inhibited the stimulatory effect of C-kinase on enzyme activity. Furthermore, the known inhibitors of C-kinase such as polymyxin-B and 1-(5-Isoquinoline sulfonyl)-2-methylpiperazine dihydrochloride (H-7) also inhibited the stimulatory effect of C-kinase on adenylate cyclase activity. In addition, in the presence of GTP the stimulatory effects of C-kinase on basal and N-Ethylcarboxamide adenosine- (NECA-), dopamine-(DA) and forskolin- (FSK) sensitive adenylate cyclase activities were augmented. On the other hand, the inhibitory effect of high concentrations of GTP on enzyme activity was attenuated by C-kinase treatment. In addition, oxotremorine inhibited adenylate cyclase activity in a concentration dependent manner, with an apparent Ki of about 10 microM and C-kinase treatment almost completely abolished this inhibition. These data suggest that C-kinase may play an important role in the regulation of adenylate cyclase activity possibly by interacting with a guanine nucleotide regulatory protein.
Anand-Srivastava
M B
MB
Clinical Research Institute of Montreal, Quebec, Canada.
Srivastava
A K
AK
D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000201:enzymology*; D002462:Cell Membrane / Q000187:drug effects / Q000201:enzymology; D005576:Colforsin / Q000494:pharmacology; D006160:Guanosine Triphosphate / Q000378:metabolism / Q000494:pharmacology; D011493:Protein Kinase C / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
D005576:Colforsin; D006160:Guanosine Triphosphate; D011493:Protein Kinase C; D000262:Adenylyl Cyclases