Limulus ventral photoreceptors contain a homologue of the alpha-subunit of mammalian Ns.
Membranes from ventral photoreceptors of Limulus were incubated with cholera toxin and [32P]NAD+. Cholera toxin catalyzes a specific ADP-ribosylation of a 43-kDa peptide from Limulus ventral photoreceptors. Possible homologies between the 43-kDa peptide of Limulus and the alpha-subunits of mammalian stimulatory, guanine nucleotide-binding regulatory component of adenylate cyclase (Ns) were investigated by comparing the electrophoretic patterns of proteolytic fragments derived from each of these peptides that are radiolabeled by [32P]NAD+ and cholera toxin. Evidence is provided for structural homology between this invertebrate peptide and mammalian Ns.
D000246:Adenosine Diphosphate Ribose / Q000378:metabolism; D000273:Adipose Tissue / Q000032:analysis; D000818:Animals; D002772:Cholera Toxin / Q000494:pharmacology; D010450:Endopeptidases / Q000378:metabolism; D019204:GTP-Binding Proteins; D006737:Horseshoe Crabs; D008099:Liver / Q000032:analysis; D008565:Membrane Proteins / Q000032:analysis; D008970:Molecular Weight; D009243:NAD / Q000378:metabolism; D010196:Pancreatic Elastase / Q000378:metabolism; D010786:Photoreceptor Cells / Q000032:analysis*; D051381:Rats; D011956:Receptors, Cell Surface / Q000032:analysis*; D012374:Rod Cell Outer Segment / Q000032:analysis; D012697:Serine Endopeptidases
D008565:Membrane Proteins; D011956:Receptors, Cell Surface; D009243:NAD; D000246:Adenosine Diphosphate Ribose; D002772:Cholera Toxin; D010450:Endopeptidases; D012697:Serine Endopeptidases; C028344:glutamyl endopeptidase; D010196:Pancreatic Elastase; D019204:GTP-Binding Proteins