title: 657WTAPELL663 motif of the photoreceptor ROS-GC1: a general phototransduction switch.
abstract: This study documents the identity of an intriguing transduction mechanism of the [Ca(2+)](i) signals by the photoreceptor ROS-GC1. Despite their distal residences and operational modes in phototransduction, the two GCAPs transmit and activate ROS-GC1 through a common Ca(2+) transmitter switch (Ca(2+)TS). A combination of immunoprecipitation, fluorescent spectroscopy, mutational analyses and reconstitution studies has been used to demonstrate that the structure of this switch is (657)WTAPELL(663). The two Ca(2+) signaling GCAP pathways converge in Ca(2+)TS, get transduced, activate ROS-GC1, generate the LIGHT signal second messenger cyclic GMP and yet functionally perform divergent operations of the phototransduction machinery. The findings define a new Ca(2+)-modulated photoreceptor ROS-GC transduction model; it is depicted and discussed for its application to processing the different shades of LIGHT.
authors.affiliation: Research Divisions of Biochemistry and Molecular Biology, The Unit of Regulatory and Molecular Biology, Salus University, 8360 Old York Road, Elkins Park, PA 19027, United States. tduda@salus.edu
authors.forename: Teresa
authors.initials: T
authors.lastname: Duda
authors.forename: Alexandre
authors.initials: A
authors.lastname: Pertzev
authors.forename: Rameshwar K
authors.initials: RK
authors.lastname: Sharma
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D006162:Guanylate Cyclase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051604:Guanylate Cyclase-Activating Proteins / Q000378:metabolism; D055537:Light Signal Transduction; D011956:Receptors, Cell Surface / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017384:Sequence Deletion
chemical_list: D051604:Guanylate Cyclase-Activating Proteins; D011956:Receptors, Cell Surface; C110715:guanylate cyclase 1; D006162:Guanylate Cyclase