title: Organization of cGMP sensing structures on the rod photoreceptor outer segment plasma membrane.
abstract: A diffusion barrier segregates the plasma membrane of the rod photoreceptor outer segment into 2 domains; one which is optimized for the conductance of ions in the phototransduction cascade and another for disk membrane synthesis. We propose the former to be named "phototransductive plasma membrane domain," and the latter to be named "disk morphogenic plasma membrane domain." Within the phototransductive plasma membrane, cGMP-gated channels are concentrated in striated membrane features, which are proximally located to the sites of active cGMP production within the disk membranes. For proper localization of cGMP-gated channel to the phototransductive plasma membrane, the glutamic acid-rich protein domain encoded in the β subunit plays a critical role. Quantitative study suggests that the disk morphogenic domain likely plays an important role in enriching rhodopsin prior to its sequestration into closed disk membranes. Thus, this and our previous studies provide new insight into the mechanism that spatially organizes the vertebrate phototransduction cascade.
authors.affiliation: a Department of Pharmacology; School of Medicine ; Case Western Reserve University ; Cleveland , OH USA.
authors.forename: Ina
authors.initials: I
authors.lastname: Nemet
authors.forename: Guilian
authors.initials: G
authors.lastname: Tian
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Imanishi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D020013:Calcium Signaling; D002417:Cattle; D003563:Cyclic CMP / Q000378:metabolism*; D054815:Cyclic Nucleotide-Gated Cation Channels / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D011485:Protein Binding; D021382:Protein Sorting Signals; D021122:Protein Subunits / Q000378:metabolism; D021381:Protein Transport; D012374:Rod Cell Outer Segment / Q000378:metabolism*; D014981:Xenopus
chemical_list: C475741:CNGA1 protein, bovine; D054815:Cyclic Nucleotide-Gated Cation Channels; D021382:Protein Sorting Signals; D021122:Protein Subunits; D003563:Cyclic CMP
keywords: CNGA1; CNGA1, cyclic nucleotide gated channel α-1; CNGB1; CNGB1, cyclic nucleotide gated channel β-1; Dend2, Dendra2; GARP, glutamic acid-rich protein; GC, guanylate cyclase; GCAP, guanylate cyclase activating protein; GPCR, G protein-coupled receptor; IS, inner segment; OS, outer segment; PDE6, phosphodiesterase 6; Rho, rhodopsin; cyclic nucleotide gated channel; morphogenesis; photoreceptor; retina; rhodopsin