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dc.contributor.authorChen, Jingen_US
dc.contributor.authorYoshida, Tatsuroen_US
dc.contributor.authorBitensky, Mark W.en_US
dc.date.accessioned2012-01-11T00:39:15Z
dc.date.available2012-01-11T00:39:15Z
dc.date.copyright2008
dc.date.issued2008-12-29
dc.identifier.citationChen, Jing, Tatsuro Yoshida, Mark W. Bitensky. "Light-induced translocation of cyclic-GMP phosphodiesterase on rod disc membranes in rat retina" Molecular Vision 14:2509-2517. (2008)
dc.identifier.issn1090-0535
dc.identifier.urihttps://hdl.handle.net/2144/3021
dc.description.abstractPURPOSE. Cyclic GMP phosphodiesterase (PDE) is the light-regulated effector enzyme of vertebrate rods. Upon photo-activation of rhodopsin followed by activation of transducin/GTP, PDE rapidly hydrolyzes 3′, 5′-cyclic GMP (cGMP) to 5′-GMP, which results in closure of cGMP-dependent ion channels and generation of a nerve signal. In the rod photoreceptors, PDE is entirely localized within the rod outer segment (ROS), a specialized compartment consisting of thousands of disc stacks. This study investigated the effects of light on the subcellular localization of PDE in ROS. METHODS. Adult rats were either dark- or light-adapted for various durations before eyes were isolated and processed for transmission electron microscopy. Immunogold electron microscopy was performed with antibodies against PDE. Lateral displacement of PDE on ROS disc membrane was analyzed from electron micrographs. PDE enzymatic activities were measured with thin layer chromatography. RESULTS. Light exposure induced translocation of PDE away from the edges of the dark-adapted disc membranes adjacent to the ROS plasma membrane. In dark-adapted ROS, a substantial portion (19±2%) of total PDE was localized near the edges of the disc membranes. Within 1 min of light exposure in the presence of GTP, over half of such PDE molecules (10±1% of total PDE) had moved away from the edges of the discs toward disc center. This light induced translocation of PDE was GTP dependent, as the effect was abolished when hydrolysis-resistant GTPγS was used in place of GTP. The percentage of PDE found near the disc edge corresponds to the fraction of PDE activity relative to maximal PDE activity revealed by limited trypsin proteolysis. CONCLUSIONS. These results suggest that light and GTP modulates lateral displacement of PDE, which might contribute to light-induced reduction of rod photoreceptor sensitivity.en_US
dc.description.sponsorshipNational Eye Institute (R01 EY14057); Juvenile Diabetes Research Foundation International fellowship (10–2008–603)en_US
dc.language.isoen
dc.publisherMolecular Visionen_US
dc.rightsThis is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.en_US
dc.rights.urihttp://creativecommons.org/licenses/by/3.0/
dc.titleLight-Induced Translocation of Cyclic-GMP Phosphodiesterase on Rod Disc Membranes in Rat Retinaen_US
dc.typeArticleen_US
dc.identifier.pmid19112528
dc.identifier.pmcid2610287


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This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Except where otherwise noted, this item's license is described as This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.