HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

J. Biol. Chem., Vol. 281, Issue 33, 23908-23921, August 18, 2006

This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 281/33/23908    most recent M600679200v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal 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 Google Scholar Google Scholar Articles by Bedoukian, M. A. Articles by Partin, K. M. Search for Related Content PubMed PubMed Citation Articles by Bedoukian, M. A. Articles by Partin, K. M. Social Bookmarking                      What's this?

Different Domains of the AMPA Receptor Direct Stargazin-mediated Trafficking and Stargazin-mediated Modulation of Kinetics^*

From the Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado 80523

Stargazin is an accessory protein of AMPA receptors that enhances surface expression and also affects the biophysical properties of the receptor. AMPA receptor domains necessary for either of these two processes have not yet been identified. Here, we used confocal imaging and electrophysiology of heterologously expressed, fluorophore-tagged GluR1, GluR2, and stargazin to study surface expression and desensitization kinetics. Stargazin-mediated trafficking was sensitive to the nature of the AMPA receptor cytoplasmic domain. The insertion of YFP after residue 15 of the truncated cytoplasmic tail of GluR1i perturbed stargazin-mediated trafficking of the receptor but not its modulation of desensitization kinetics. This construct also failed to permit fluorescence resonance energy transfer (FRET) with stargazin in the endoplasmic reticulum (ER), whereas FRET between fluorophore-tagged stargazin and non-truncated AMPA receptors demonstrated a specific interaction between these proteins, both in the ER and the plasma membrane. Rather than encoding a specific binding site, the fluorophore-tagged C terminus may restrict access to one or more ER retention sites. Although perturbations of the C terminus impeded stargazin-mediated trafficking to the plasma membrane, the effects of stargazin on the biophysical properties of AMPA receptors (i.e. modulation of desensitization) remained intact. These data provide strong evidence that the AMPA receptor domains required for stargazin modulation of gating and trafficking are separable.

Received for publication, January 23, 2006 , and in revised form, June 14, 2006.

^* This work was supported by National Institutes of Health Predoctoral Training Grant NS43115-02 (to M. A. B.) and Grant R01MH64700 (to K. M. P.). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

The on-line version of this article (available at http://www.jbc.org) contains supplemental Figs. S1 and S2.

¹ To whom correspondence should be addressed: Dept. of Biomedical Sciences, Div. of Neuroscience, CO State University, Fort Collins, CO 80523-1617. Tel.: 970-491-2263; Fax: 970-491-7907; E-mail: kpartin{at}lamar.colostate.edu.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				M. A. Bedoukian, J. D. Whitesell, E. J. Peterson, C. M. Clay, and K. M. Partin The Stargazin C Terminus Encodes an Intrinsic and Transferable Membrane Sorting Signal J. Biol. Chem., January 18, 2008; 283(3): 1597 - 1600. [Abstract] [Full Text] [PDF]

				A. S. Kato, W. Zhou, A. D. Milstein, M. D. Knierman, E. R. Siuda, J. E. Dotzlaf, H. Yu, J. E. Hale, E. S. Nisenbaum, R. A. Nicoll, et al. New Transmembrane AMPA Receptor Regulatory Protein Isoform, {gamma}-7, Differentially Regulates AMPA Receptors J. Neurosci., May 2, 2007; 27(18): 4969 - 4977. [Abstract] [Full Text] [PDF]