Journal
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
Volume 334, Issue 1, Pages 96-101Publisher
ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI: 10.1016/j.bbrc.2005.06.074
Keywords
invertebrate fertilization; acrosome reaction; chemotaxis; cyclic nucleotides; flagellar motility; ion channels
Categories
Funding
- NICHD NIH HHS [HD 12986] Funding Source: Medline
Ask authors/readers for more resources
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.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available