title: Plasma membrane-associated component(s) that confer(s) cholera toxin sensitivity to adenylate cyclase.
abstract: Incubation of crude normal rat kidney membranes with activated cholera toxin in the presence of DTP, ATP and NAD results in a 10--20 fold stimulation of adenylate cyclase activity. Optimal choleragen activation f the cyclase is shown to be dependent upon the presence of a plasma membrane-associated reconstituting activity, which can be dissociated from the membranes by washing with 10 mM potassium phosphate buffer, pH 7.5, containing 5 mM EDTA and 0.1 mM dithiothreitol. choleragen-catalyzed ADP ribosylation of plasma membrane substrate proteins also requires the presence of reconstituting activity factor. Sephadex G-150 filtration of solubilized reconstituting activity shows a peak activity eluting in the region corresponding to a protein with a molecular weight of approx. 13,000. Reconstituting activity is eluted from DEAE-cellulose at a salt concentration of 40--100 mM KCl. This active factor is not destroyed by trypsin treatment or by boiling for 30 min. These observations indicate that an endogenous membrane-associated factor, along with GTP, may be involved in modulating the ability of choleragen to activate adenylate cyclase.
mesh_terms: D000246:Adenosine Diphosphate Ribose / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D002462:Cell Membrane / Q000201:enzymology*; D002772:Cholera Toxin / Q000494:pharmacology*; D002850:Chromatography, Gel; D003600:Cytosol / Q000201:enzymology; D004355:Drug Stability; D004789:Enzyme Activation / Q000187:drug effects; D006160:Guanosine Triphosphate / Q000494:pharmacology; D007668:Kidney / Q000201:enzymology*; D008565:Membrane Proteins / Q000378:metabolism; D009243:NAD / Q000494:pharmacology; D051381:Rats
chemical_list: D008565:Membrane Proteins; D009243:NAD; D000246:Adenosine Diphosphate Ribose; D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate; D002772:Cholera Toxin; D000262:Adenylyl Cyclases