rdf:type |
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lifeskim:mentions |
|
pubmed:issue |
2
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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.
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pubmed:language |
eng
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pubmed:journal |
|
pubmed:citationSubset |
IM
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pubmed:chemical |
|
pubmed:status |
MEDLINE
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pubmed:month |
Feb
|
pubmed:issn |
1748-7838
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pubmed:author |
|
pubmed:issnType |
Electronic
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pubmed:volume |
21
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
305-15
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pubmed:meshHeading |
pubmed-meshheading:20838418-Amino Acid Substitution,
pubmed-meshheading:20838418-Calcium,
pubmed-meshheading:20838418-Calcium Channels,
pubmed-meshheading:20838418-Cell Line,
pubmed-meshheading:20838418-Humans,
pubmed-meshheading:20838418-Membrane Proteins,
pubmed-meshheading:20838418-Mutation,
pubmed-meshheading:20838418-Neoplasm Proteins,
pubmed-meshheading:20838418-Patch-Clamp Techniques,
pubmed-meshheading:20838418-Protein Binding,
pubmed-meshheading:20838418-Protein Structure, Tertiary,
pubmed-meshheading:20838418-Protein Subunits,
pubmed-meshheading:20838418-Recombinant Fusion Proteins
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pubmed:year |
2011
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pubmed:articleTitle |
Graded activation of CRAC channel by binding of different numbers of STIM1 to Orai1 subunits.
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pubmed:affiliation |
National Key Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
|