JCB logo
MBoC5 from Garland Science
  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents
Published 28 October 2002. doi:10.1083/jcb.200207060
This Article
Right arrow Full Text
Right arrow PDF (Full Text)
Right arrow PPT slides of all figures
Right arrow Alert me when this article is cited
Right arrow Citation Map
Services
Right arrow Email this article
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new content in the JCB
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Skerrett, I.M.
Right arrow Articles by Nicholson, B.J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Skerrett, I.M.
Right arrow Articles by Nicholson, B.J.
Right arrowPubmed/NCBI databases
*Compound via MeSH
*Substance via MeSH
Hazardous Substances DB
*CYSTEINE
Related Collections
Right arrowRelated Article
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?
© The Rockefeller University Press, 0021-9525/2002/10/349 $5.00
The Journal of Cell Biology, Volume 159, Number 2, 349-360

Article

 Identification of amino acid residues lining the pore of a gap junction channel

I.M. Skerrett1, J. Aronowitz1, J.H. Shin1, G. Cymes2, E. Kasperek1, F.L. Cao3 and B.J. Nicholson1

1 Department of Biological Sciences, State University of New York at Buffalo, Buffalo, NY 14260
2 Department of Physiology and Biophysics, State University of New York at Buffalo, Buffalo, NY 14214
3 Department of Genetics, Emory School of Medicine, Atlanta, GA 30322

Address correspondence to B.J. Nicholson, Dept. of Biological Sciences, 615 Cooke Hall, State University of New York at Buffalo, Buffalo, NY 14260-1300. Tel.: (716) 645-3344. Fax: (716) 645-2871. E-mail: bjn{at}acsu.buffalo.edu

Gap junctions represent a ubiquitous and integral part of multicellular organisms, providing the only conduit for direct exchange of nutrients, messengers and ions between neighboring cells. However, at the molecular level we have limited knowledge of their endogenous permeants and selectivity features. By probing the accessibility of systematically substituted cysteine residues to thiol blockers (a technique called SCAM), we have identified the pore-lining residues of a gap junction channel composed of Cx32. Analysis of 45 sites in perfused Xenopus oocyte pairs defined M3 as the major pore-lining helix, with M2 (open state) or M1 (closed state) also contributing to the wider cytoplasmic opening of the channel. Additional mapping of a close association between M3 and M4 allowed the helices of the low resolution map (Unger et al., 1999. Science. 283:1176–1180) to be tentatively assigned to the connexin transmembrane domains. Contrary to previous conceptions of the gap junction channel, the residues lining the pore are largely hydrophobic. This indicates that the selective permeabilities of this unique channel class may result from novel mechanisms, including complex van der Waals interactions of permeants with the pore wall, rather than mechanisms involving fixed charges or chelation chemistry as reported for other ion channels.

Key Words: connexin32; SCAM; pore lining; accessibility; Xenopus oocyte expression


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

Related Article

Gazing into the gap
Alan W. Dove
J. Cell Biol. 2002 159: 199. [Full Text] [PDF]



This article has been cited by other articles:



  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents