Detection of Ca2+-dependent cyclic GMP binding protein in frog rod outer segments.
For the identification of the cGMP-sensitive ion channel protein of frog rod outer segments (ROS), we analyzed cGMP binding proteins in the ROS by photoaffinity labeling with [3H]cGMP. We found three cGMP binding polypeptides (66 kDa, 92 kDa and 100 kDa) in the membrane protein fraction of ROS. cGMP binding to the 66 kDa polypeptide required the addition of 2 mM CaCl2. We propose that this polypeptide corresponds to the cGMP-activated channel protein reported by Cook et al. [(1987) Proc. Natl. Acad. Sci. USA 84, 585-589]. The 100 kDa and 92 kDa polypeptides are subunits of the cGMP phosphodiesterase.
D000818:Animals; D002122:Calcium Chloride / Q000494:pharmacology*; D002352:Carrier Proteins / Q000302:isolation & purification / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins; D007700:Kinetics; D008970:Molecular Weight; D010786:Photoreceptor Cells / Q000378:metabolism*; D011892:Rana catesbeiana; D011956:Receptors, Cell Surface / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism; D012374:Rod Cell Outer Segment / Q000378:metabolism*
D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D011956:Receptors, Cell Surface; C022994:cyclic GMP-binding protein; D006152:Cyclic GMP; D002122:Calcium Chloride