QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

HOME  |   SEARCH  |   ARCHIVE  |   SUBSCRIBE  |   CONTACT  |   HELP

This Article Full Text Full Text (PDF) Submit an eLetter Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (16) Citing Articles via Google Scholar Google Scholar Articles by Kasahara, T. Articles by Fukada, Y. Search for Related Content PubMed PubMed Citation Articles by Kasahara, T. Articles by Fukada, Y.

Next Article 

The Journal of Neuroscience, September 1, 2002, 22(17):7321-7325

BRIEF COMMUNICATION
Opsin-G₁₁-Mediated Signaling Pathway for Photic Entrainment of the Chicken Pineal Circadian Clock

Takaoki Kasahara^{1, 3}, Toshiyuki Okano^{1, 3}, Tatsuya Haga^{2, 3}, and Yoshitaka Fukada^{1, 3}

¹ Department of Biophysics and Biochemistry, Graduate School of Science, ² Department of Neurochemistry, Faculty of Medicine, The University of Tokyo, Tokyo 113-0033, Japan, and ³ Core Research for Evolutional Science and Technology of Japan Science and Technology Corporation, Tokyo 105-0011, Japan

Light is a major environmental signal for entrainment of the circadian clock, but little is known about the intracellular phototransduction pathway triggered by light activation of the photoreceptive molecule(s) responsible for the phase shift of the clock in vertebrates. The chicken pineal gland and retina contain the autonomous circadian oscillators together with the photic entrainment pathway, and hence they represent useful experimental models for the clock system. Here we show the expression of G₁₁, an  subunit of heterotrimeric G-protein, in both tissues by cDNA cloning, Northern blot, and Western blot analyses. G₁₁ immunoreactivity was colocalized with pinopsin in the chicken pineal cells and also with rhodopsin in the outer segments of retinal photoreceptor cells, suggesting functional coupling of G₁₁ with opsins in the clock-containing photosensitive tissues. The physical interaction was examined by coimmunoprecipitation experiments, the results of which provided evidence for light- and GTP-dependent coupling between rhodopsin and G₁₁. To examine whether activation of endogenous G₁₁ leads to a phase shift of the oscillator, G_q/11-coupled m1-type muscarinic acetylcholine receptor (mAChR) was ectopically expressed in the cultured pineal cells. Subsequent treatment of the cells with carbamylcholine (CCh), an agonist of mAChR, induced phase-dependent phase shifts of the melatonin rhythm in a manner very similar to the effect of light. In contrast, CCh treatment induced no measurable effect on the rhythm of nontransfected (control) cells or cells expressing G_i/o-coupled m2-type mAChR, indicating selectivity of the G-protein activation. Together, our results demonstrate the existence of a G₁₁-mediated opsin-signaling pathway contributing to the photic entrainment of the circadian clock.

Key words: G₁₁; phototransduction; circadian rhythm; pinopsin; pineal gland; retina

---

Copyright © 2002 Society for Neuroscience  0270-6474/02/22177321-05$05.00/0

This article has been cited by other articles:

				A. Rajala, R. E. Anderson, J.-X. Ma, J. Lem, M. R. Al-Ubaidi, and R. V. S. Rajala G-protein-coupled Receptor Rhodopsin Regulates the Phosphorylation of Retinal Insulin Receptor J. Biol. Chem., March 30, 2007; 282(13): 9865 - 9873. [Abstract] [Full Text] [PDF]

				T. Okano and Y. Fukada Chicktacking Pineal Clock J. Biochem., December 1, 2003; 134(6): 791 - 797. [Abstract] [Full Text] [PDF]

				M. J. Bailey, P. D. Beremand, R. Hammer, D. Bell-Pedersen, T. L. Thomas, and V. M. Cassone Transcriptional Profiling of the Chick Pineal Gland, a Photoreceptive Circadian Oscillator and Pacemaker Mol. Endocrinol., October 1, 2003; 17(10): 2084 - 2095. [Abstract] [Full Text] [PDF]

				A. Mendez, J. Lem, M. Simon, and J. Chen Light-Dependent Translocation of Arrestin in the Absence of Rhodopsin Phosphorylation and Transducin Signaling J. Neurosci., April 15, 2003; 23(8): 3124 - 3129. [Abstract] [Full Text] [PDF]

Home  |   Search  |   Archive  |   Subscribe  |   Contact  |   Help