Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2011-2-3
pubmed:abstractText
The Ca(2+) release-activated Ca(2+) (CRAC) channel pore is formed by Orai1 and gated by STIM1 after intracellular Ca(2+) store depletion. To resolve how many STIM1 molecules are required to open a CRAC channel, we fused different numbers of Orai1 subunits with functional two-tandem cytoplasmic domains of STIM1 (residues 336-485, designated as S domain). Whole-cell patch clamp recordings of these chimeric molecules revealed that CRAC current reached maximum at a stoichiometry of four Orai1 and eight S domains. Further experiments indicate that two-tandem S domains specifically interact with the C-terminus of one Orai1 subunit, and CRAC current can be gradually increased as more Orai1 subunits can interact with S domains or STIM1 proteins. Our data suggest that maximal opening of one CRAC channel requires eight STIM1 molecules, and support a model that the CRAC channel activation is not in an "all-or-none" fashion but undergoes a graded process via binding of different numbers of STIM1.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1748-7838
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
21
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
305-15
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Graded activation of CRAC channel by binding of different numbers of STIM1 to Orai1 subunits.
pubmed:affiliation
National Key Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't