A new hyperpolarization-activated, cyclic nucleotide-gated channel from sea urchin sperm flagella

被引：31

作者：

Galindo, BE ^{[1
]}

Neill, AT ^{[1
]}

Vacquier, VD ^{[1
]}

机构：

[1] Univ Calif San Diego, Scripps Inst Oceanog, Ctr Marine Biotechnol & Biomed, La Jolla, CA 92093 USA

来源：

BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS | 2005年 / 334卷 / 01期

关键词：

invertebrate fertilization; acrosome reaction; chemotaxis; cyclic nucleotides; flagellar motility; ion channels;

D O I：

10.1016/j.bbrc.2005.06.074

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

A sea urchin sperm flagellar hyperpolarization-activated, cyclic nucleotide-gated (HCN) channel is known (SpHCN1) that is modulated by cAMP. Here, we describe a second flagellar HCN channel (SpHCN2) cloned from the same sea urchin species. SpHCN2 is 638 amino acids compared to 767 for SpHCN1. SpHCN2 has all the domains of an HCN channel, including six transmembrane segments (S1-S6), the ion pore, and the cyclic nucleotide-binding domain. The two full-length proteins are 33% identical and 51% similar. The six transmembrane segments vary from 46-79% identity. S4, which is the voltage sensor, is 79% identical between the two proteins. The ion selectivity filter sequence is GYG in the ion pore of SpHCN1 and GFG in SpHCN2. By sequence, SpHCN2 is 73.5 kDa, but it migrates on SDS-PAGE at 64 kDa. Western immunoblots show localization to flagella, which is confirmed by immunofluorescence. A neighbor-joining tree shows that SpHCN2 is basal to all known HCN channels. SpHCN2 might be the simplest pacemaker channel yet discovered. (c) 2005 Elsevier Inc. All rights reserved.

引用

页码：96 / 101

页数：6

共 25 条

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