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


     

(Investigative Ophthalmology and Visual Science. 2007;48:901-906.)
© 2007 by The Association for Research in Vision and Ophthalmology, Inc.
DOI:  10.1167/iovs.06-0824
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 HighWire
Right arrow Citing Articles via ISI Web of Science (1)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Chae, K.-S.
Right arrow Articles by Dryer, S. E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Chae, K.-S.
Right arrow Articles by Dryer, S. E.

Tyrosine Phosphorylation of cGMP-Gated Ion Channels Is under Circadian Control in Chick Retina Photoreceptors

Kwon-Seok Chae,1,2 Gladys Y.-P. Ko,2,3 and Stuart E. Dryer4

1From the School of Life Sciences and Biotechnology, Korea University, Seoul, Korea; the 3Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas; and the 4Department of Biology and Biochemistry, University of Houston, Houston, Texas.

PURPOSE. To investigate the role of tyrosine phosphorylation in circadian regulation of cGMP-gated cation channels (CNGCs) of chicken cone photoreceptors.

METHODS. Chick retinas were studied on the second day of constant darkness (DD) after several days of entrainment to 12:12 hr light–dark (LD) cycles in vitro. Inside-out patch recordings were made during the subjective day and subjective night to quantify circadian changes in the sensitivity of CNGCs to activation by cGMP after treatment with various tyrosine kinase and tyrosine phosphatase inhibitors. Immunoprecipitation and immunoblot analysis were also used to examine tyrosine phosphorylation of CNGCs and closely associated proteins after separation by conventional and two-dimensional SDS-PAGE.

RESULTS. Treatment with tyrosine kinase inhibitors caused a significant decrease in K1/2 for cGMP activation of CNGCs in patches excised from cones during the subjective day, but had no effect on K1/2 during the subjective night. Conversely, treatment with a tyrosine phosphatase inhibitor caused a significant increase in the K1/2 of CNGCs in patches excised during the subjective night but had no effect on channel K1/2 during the subjective day. Broad spectrum serine-threonine phosphatase inhibitors had no effect. An 85-kDa tyrosine polypeptide that coimmunoprecipitated with CNGC {alpha}-subunits was detectable at higher levels during the subjective day than during the subjective night. CNGC {alpha}-subunits were not tyrosine phosphorylated as a function of the time of day.

CONCLUSIONS. Circadian control of cone CNGCs appears to entail elevated daytime tyrosine phosphorylation of an ~85-kDa auxiliary protein or another subunit of the CNGCs.




This article has been cited by other articles:


Home page
 J. Neurosci.Home page
S.-K. Chen, G. Y.-P. Ko, and S. E. Dryer
Somatostatin Peptides Produce Multiple Effects on Gating Properties of Native Cone Photoreceptor cGMP-Gated Channels That Depend on Circadian Phase and Previous Illumination
J. Neurosci., November 7, 2007; 27(45): 12168 - 12175.
[Abstract] [Full Text] [PDF]


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