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

J. Biol. Chem., Vol. 280, Issue 25, 23945-23959, June 24, 2005

This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 280/25/23945    most recent M414078200v1 Submit a Letter to Editor 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 PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Li, X. Articles by Herlitze, S. Search for Related Content PubMed PubMed Citation Articles by Li, X. Articles by Herlitze, S. Social Bookmarking                      What's this?

G Protein ₂ Subunit-derived Peptides for Inhibition and Induction of G Protein Pathways

EXAMINATION OF VOLTAGE-GATED Ca²⁺ AND G PROTEIN INWARDLY RECTIFYING K⁺ CHANNELS^*

Xiang Li, Alexander Hümmer, Jing Han, Mian Xie, Katya Melnik-Martinez, Rosa L. Moreno, Matthias Buck¶, Melanie D. Mark, and Stefan Herlitze||

From the Department of Neurosciences and the ^¶Department of Physiology and Biophysics, Case Western Reserve University, School of Medicine, Cleveland, Ohio 44106 and Flyion GmbH, Waldhäuserstrasse 64, D-72076 Tübingen, Germany

Voltage-gated Ca²⁺ channels of the N-, P/Q-, and R-type and G protein inwardly rectifying K⁺ channels (GIRK) are modulated via direct binding of G proteins. The modulation is mediated by G protein subunits. By using electrophysiological recordings and fluorescence resonance energy transfer, we characterized the modulatory domains of the G protein subunit on the recombinant P/Q-type channel and GIRK channel expressed in HEK293 cells and on native non-L-type Ca²⁺ currents of cultured hippocampal neurons. We found that G₂ subunit-derived deletion constructs and synthesized peptides can either induce or inhibit G protein modulation of the examined ion channels. In particular, the 25-amino acid peptide derived from the G₂ N terminus inhibits G protein modulation, whereas a 35-amino acid peptide derived from the G₂ C terminus induced modulation of voltage-gated Ca²⁺ channels and GIRK channels. Fluorescence resonance energy transfer (FRET) analysis of the live action of these peptides revealed that the 25-amino acid peptide diminished the FRET signal between G protein ₂₃ subunits, indicating a reorientation between G protein ₂₃ subunits in the presence of the peptide. In contrast, the 35-amino acid peptide increased the FRET signal between GIRK1,2 channel subunits, similarly to the G-mediated FRET increase observed for this GIRK subunit combination. Circular dichroism spectra of the synthesized peptides suggest that the 25-amino acid peptide is structured. These results indicate that individual G protein subunit domains can act as independent, separate modulatory domains to either induce or inhibit G protein modulation for several effector proteins.

Received for publication, December 14, 2004 , and in revised form, February 28, 2005.

^* This work was supported by National Institutes of Health Grant R01 NS42623 (to S. H.). 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 a Table and Figs. 1, 2, 3, 4.

^|| To whom correspondence should be addressed: Dept. of Neurosciences, Case Western Reserve University School of Medicine, Rm. E604, 10900 Euclid Ave., Cleveland, OH 44106-4975. Tel.: 216-368-1804; Fax: 216-368-4650; E-mail: sxh106{at}cwru.edu.

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

This article has been cited by other articles:

				M. Xie, X. Li, J. Han, D. L. Vogt, S. Wittemann, M. D. Mark, and S. Herlitze Facilitation versus depression in cultured hippocampal neurons determined by targeting of Ca2+ channel Cav{beta}4 versus Cav{beta}2 subunits to synaptic terminals J. Cell Biol., July 24, 2007; 178(3): 489 - 502. [Abstract] [Full Text] [PDF]

				S. D. DePuy, J. Yao, C. Hu, W. McIntire, I. Bidaud, P. Lory, F. Rastinejad, C. Gonzalez, J. C. Garrison, and P. Q. Barrett The molecular basis for T-type Ca2+ channel inhibition by G protein beta2{gamma}2 subunits PNAS, September 26, 2006; 103(39): 14590 - 14595. [Abstract] [Full Text] [PDF]

				X. Li, D. V. Gutierrez, M. G. Hanson, J. Han, M. D. Mark, H. Chiel, P. Hegemann, L. T. Landmesser, and S. Herlitze Fast noninvasive activation and inhibition of neural and network activity by vertebrate rhodopsin and green algae channelrhodopsin PNAS, December 6, 2005; 102(49): 17816 - 17821. [Abstract] [Full Text] [PDF]