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

J. Biol. Chem., Vol. 282, Issue 24, 17720-17728, June 15, 2007

This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 282/24/17720    most recent M607063200v1 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 Google Scholar Google Scholar Articles by Li, H. Articles by Ding, J. Search for Related Content PubMed PubMed Citation Articles by Li, H. Articles by Ding, J. Social Bookmarking                      What's this?

Interaction Sites between the Slo1 Pore and the NH₂ Terminus of the 2 Subunit, Probed with a Three-residue Sensor^*

Hui Li¹, Jing Yao¹, Xiaotian Tong, Zhaohua Guo, Ying Wu, Liang Sun, Na Pan, Houming Wu, Tao Xu^¶2, and Jiuping Ding³

From the Institute of Biochemistry and Biophysics, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China, the ^¶National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Science, Beijing 100101, China, and the State Key Laboratory of Bio-organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China

Calcium- and voltage-gated (BK) K⁺ channels encoded by Slo1 play an essential role in nervous systems. Although it shares many common features with voltage-dependent K_V channels, the BK channel exhibits differences in gating and inactivation. Using a mutant in which FWI replaces three residues (FIW) in the NH₂ terminus of wild-type 2-subunits, in conjunction with alanine-scanning mutagenesis of the Slo1 S6 segment, we identify that the NH₂ terminus of 2-subunits interacts with the residues near the cytosolic superficial mouth of BK channels during inactivation. The cytosolic blockers did not share the sites with NH₂ terminus of 2-subunits. A novel blocking-inactivating scheme was proposed to account for the observed non-competition inactivation. Our results also suggest that the residue Ile-323 plays a dual role in interacting with the NH₂ terminus of 2-subunits and modulating the gating of BK channels.

Received for publication, July 25, 2006 , and in revised form, February 7, 2007.

^* This work was supported by the National Science Foundation of China (Grants 30470449, 30630020, 30670502, 30470646, 30500117, and 20132030), the Major State Basic Research Program of P. R. China (Grant 2004CB720000), and the Chinese Academy of Sciences (Grant KGCX2-SW-213-05). 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 and Tables S1 and S2.

¹ Both authors contributed equally to this work.

² To whom correspondence may be addressed: Tel.: 86-10-6488-8469; Fax: 86-10-6486-7566; E-mail: xutao{at}ibp.ac.cn. ³ To whom correspondence may be addressed: Tel.: 86-27-8779-2153; Fax: 86-27-8779-2024; E-mail: jpding{at}mail.hust.edu.cn.

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