Linked Life Data

10428816

Source:http://linkedlifedata.com/resource/pubmed/id/10428816

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
32
pubmed:dateCreated
1999-9-2
pubmed:abstractText
We have investigated the molecular determinants that mediate the differences in voltage-dependent inactivation properties between rapidly inactivating (R-type) alpha(1E) and noninactivating (L-type) alpha(1C) calcium channels. When coexpressed in human embryonic kidney cells with ancillary beta(1b) and alpha(2)-delta subunits, the wild type channels exhibit dramatically different inactivation properties; the half-inactivation potential of alpha(1E) is 45 mV more negative than that observed with alpha(1C), and during a 150-ms test depolarization, alpha(1E) undergoes 65% inactivation compared with only about 15% for alpha(1C). To define the structural determinants that govern these intrinsic differences, we have created a series of chimeric calcium channel alpha(1) subunits that combine the major structural domains of the two wild type channels, and we investigated their voltage-dependent inactivation properties. Each of the four transmembrane domains significantly affected the half-inactivation potential, with domains II and III being most critical. In particular, substitution of alpha(1C) sequence in domains II or III with that of alpha(1E) resulted in 25-mV negative shifts in half-inactivation potential. Similarly, the differences in inactivation rate were predominantly governed by transmembrane domains II and III and to some extent by domain IV. Thus, voltage-dependent inactivation of alpha(1E) channels is a complex process that involves multiple structural domains and possibly a global conformational change in the channel protein.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
6
pubmed:volume
274
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
22428-36
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Multiple structural domains contribute to voltage-dependent inactivation of rat brain alpha(1E) calcium channels.
pubmed:affiliation
Department of Pharmacology and Therapeutics, Neuroscience Research Group, University of Calgary, Calgary, Alberta T2N 4N1, Canada.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't