Original Article
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World J Biol Chem. May 26, 2014; 5(2): 254-268
Published online May 26, 2014. doi: 10.4331/wjbc.v5.i2.254
Binding of rhodopsin and rhodopsin analogues to transducin, rhodopsin kinase and arrestin-1
Nelson A Araujo, Carlos E Sanz-Rodríguez, José Bubis
Nelson A Araujo, Carlos E Sanz-Rodríguez, José Bubis, Departamento de Biología Celular, Universidad Simón Bolívar, Caracas 1081-A, Venezuela
Nelson A Araujo, Coordinación del Postgrado en Química, Universidad Simón Bolívar, Caracas 1081-A, Venezuela
Carlos E Sanz-Rodríguez, Coordinación del Postgrado en Ciencias Biológicas, Universidad Simón Bolívar, Caracas 1081-A, Venezuela
Carlos E Sanz-Rodríguez, Laboratorio de Dinámica Estocástica, Centro de Física, Instituto Venezolano de Investigaciones Científicas, Caracas 1020-A, Venezuela
Author contributions: Bubis J designed the research; Araujo NA, Sanz-Rodríguez CE and Bubis J performed the research; Araujo NA, Sanz-Rodríguez CE and Bubis J analyzed the data, and wrote the paper.
Supported by Grants from FONACIT, Caracas, Venezuela, No.S1-2000000514 and No.LAB-2000001639; and from Decanato de Investigación y Desarrollo, Universidad Simón Bolívar, Caracas, Venezuela, No.S1-IN-CB-001-09
Correspondence to: José Bubis, PhD, Departamento de Biología Celular, Universidad Simón Bolívar, Apartado 89000, Valle de Sartenejas, Baruta, Caracas 1081-A, Venezuela. jbubis@usb.ve
Telephone: +58-212-9064219 Fax: +58-212-9063064.
Received: November 24, 2013
Revised: February 10, 2014
Accepted: April 17, 2014
Published online: May 26, 2014
Processing time: 199 Days and 7.5 Hours
Core Tip

Core tip: Rhodopsin is a specialized G protein-coupled receptors composed of a single polypeptide chain, opsin, and a covalently linked 11-cis-retinal. It is well known that rhodopsin uses the 11-cis form of retinal exclusively as the chromophore. Retinal analogues have long been used to probe the chromophore binding pocket and to study ligand-protein relationships to better understand the photochemical cis-trans isomerization of rhodopsin. However, little is known about the interactions of rhodopsin analogues with other proteins in the visual cascade. Here, we were able to reconstitute a rhodopsin analogue containing 13-cis-retinal. We compared the binding of reconstituted rhodopsin, 9-cis-retinal-rhodopsin and 13-cis-retinal-rhodopsin to transducin, rhodopsin kinase and arrestin-1, both in the dark and under illumination. Interestingly, we found that in the dark the rhodopsin analogue containing the 13-cis isomer of retinal appears to fold in a pseudo-active conformation that mimics the active photointermediate of rhodopsin.