IOVS BJO
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

(Investigative Ophthalmology and Visual Science. 2007;48:3350-3355.)
© 2007 by The Association for Research in Vision and Ophthalmology, Inc.
DOI:  10.1167/iovs.07-0126
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via ISI Web of Science (2)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Chen, J.
Right arrow Articles by McGinnis, J. F.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Chen, J.
Right arrow Articles by McGinnis, J. F.

Light Threshold–Controlled Cone {alpha}-Transducin Translocation

Junping Chen,1,2 Mingyuan Wu,3 Steven A. Sezate,2 and James F. McGinnis1,2,4,5

1From the Oklahoma Center for Neuroscience, the 2Dean A. McGee Eye Institute, and the 3Departments of Physiology, 4Cell Biology, and 5Ophthalmology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.

PURPOSE. Light-induced translocation of rod {alpha}-transducin (rT{alpha}, GNAT1) has been recognized as one of the mechanisms for light adaptation in rods. However, cone {alpha}-transducin (cT{alpha}, GNAT2) has not been shown to have such light-dependent redistribution. To investigate potential reasons for the restriction of cT{alpha} to the cone outer segment, the authors established a transient transgenic strategy to express cone T{alpha} within rod photoreceptor cells, and the location of the cone T{alpha} within rods and cones was examined under different light conditions.

METHODS. Vector DNA that expresses cT{alpha} and green fluorescent protein (GFP) bicistronically under control of the cytomegalovirus (CMV) promoter was injected subretinally into the eyes of neonatal rats, and this was followed by electroporation. The localization of cT{alpha} in rods and cones under different light conditions was determined by immunofluorescent techniques.

RESULTS. Injection of the cDNA constructs resulted in the successful transient transfection of retinal cells. When cT{alpha} was exogenously expressed in rods, its localization paralleled that of endogenous rT{alpha} under light and dark conditions. Further experiments, with higher intensity light (7000 lux), demonstrated that endogenous cT{alpha} can also translocate in cone photoreceptor cells to the same extent it does in rods under 600 lux light.

CONCLUSIONS. The authors successfully established an in vivo transient retinal transfection model. The demonstration of cT{alpha} translocation in rods indicates cT{alpha} is not inherently prevented from translocating. The novel observation of cT{alpha} translocation under high-intensity light suggests a light threshold regulates the redistribution of cT{alpha} possibly as a protective response against very bright light.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2007 by the Association for Research in Vision and Ophthalmology