title: p19 detected in the rat retina and pineal gland is a guanylyl cyclase-activating protein (GCAP).
abstract: The Ca(2+)-dependent activation of retina-specific guanylyl cyclase (retGC) is mediated by guanylyl cyclase-activating proteins (GCAPs). Here we report for the first time detection of a 19 kDa protein (p19) with GCAP properties in extracts of rat retina and pineal gland. Both extracts stimulate synthesis of cGMP in rod outer segment (ROS) membranes at low (30 nM) but not at high (1 microM) concentrations of Ca(2+). At low Ca(2+), immunoaffinity purified p19 activates guanylyl cyclase(s) in bovine ROS and rat retinal membranes. Moreover, p19 is recognized by antibodies against bovine GCAP1 and, similarly to other GCAPs, exhibits a Ca(2+)-dependent electrophoretic mobility shift.
authors.affiliation: Department of Biogenic Amines, Polish Academy of Sciences, Łódź, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Dejda
authors.forename: Izabela
authors.initials: I
authors.lastname: Matczak
authors.forename: Wojciech A
authors.initials: WA
authors.lastname: Gorczyca
mesh_terms: D000818:Animals; D000906:Antibodies / Q000276:immunology; D015153:Blotting, Western; D002135:Calcium-Binding Proteins / Q000737:chemistry* / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D002417:Cattle; D002462:Cell Membrane / Q000201:enzymology; D004591:Electrophoresis, Polyacrylamide Gel; D006162:Guanylate Cyclase / Q000378:metabolism; D051604:Guanylate Cyclase-Activating Proteins; D051379:Mice; D008970:Molecular Weight; D010870:Pineal Gland / Q000378:metabolism*; D051381:Rats; D011994:Recombinant Proteins; D012160:Retina / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D012374:Rod Cell Outer Segment / Q000166:cytology / Q000378:metabolism
chemical_list: D000906:Antibodies; D002135:Calcium-Binding Proteins; D051604:Guanylate Cyclase-Activating Proteins; C496737:Guca1a protein, mouse; D011994:Recombinant Proteins; D006162:Guanylate Cyclase