Linked Life Data

14676187

Source:http://linkedlifedata.com/resource/pubmed/id/14676187

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
2004-3-8
pubmed:abstractText
Gap-junctional channels are formed by two connexons or gap-junctional hemichannels in series, with each connexon conformed by six connexin molecules. As with other membrane proteins, structural information on connexons can potentially be obtained with techniques that take advantage of the highly specific thiol chemistry by positioning Cys residues at locations of interest, ideally in an otherwise Cys-less protein. It has been shown that conserved Cys residues located in the extracellular loops of connexins are essential for the docking of connexons from adjacent cells, preventing the formation of functional gap-junctional channels. Here we engineered a Cys-less version of connexin 43 (Cx43) and assessed its function using a Xenopus oocyte expression system. The Cys-less protein was expressed at the plasma membrane and did not form gap-junctional channels but formed hemichannels that behave similarly to those formed by Cx43 in terms of permeation to carboxyfluorescein. The carboxyfluorescein permeability of Cys-less hemichannels was increased by protein kinase C inhibition, like the wild-type Cx43 hemichannels. We generated a protein with a single Cys in a position (residue 34) thought to face the channel pore and show that thiol modification of the Cys abolishes the carboxyfluorescein permeability. We conclude that Cysless Cx43 forms regulated functional hemichannels, and therefore Cys-less Cx43 is a useful tool for future structural studies.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
12
pubmed:volume
279
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9689-92
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Functional expression in Xenopus oocytes of gap-junctional hemichannels formed by a cysteine-less connexin 43.
pubmed:affiliation
Membrane Protein Laboratory, Sealy Center for Structural Biology, and Department of Physiology and Biophysics, The University of Texas Medical Branch, Galveston, Texas 77555-0437, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't