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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
2
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pubmed:dateCreated |
1981-5-28
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pubmed:abstractText |
We have uniformly labeled calmodulin with tetramethyl rhodamine isothiocyanate (CaM-RITC) and used the derivative as a molecular probe in order to identify available, unoccupied calmodulin-binding sites. In mildly fixed (3% formalin) cultured 3T3 cells, the biologically active CaM-RITC bound predominantly to mitochondria. Binding was markedly reduced in the presence of 1 mM EGTA. Stelazine, a phenothiozine which binds to calmodulin, prevented the interaction of CaM-RITC with mitochondrial sites. A 10 fold excess of unlabeled CaM competitively inhibited binding. Fluorescently labeled troponin C and parvalbumin did not bind to mitochondria on any other cellular organelle. Rhodamine (TMRITC) alone did not bind to 3T3 mitochondria. Similar results were obtained using 125I-calmodulin binding to isolated rat liver mitochondria. When solubilized mitochondrial proteins were subjected to calmodulin-Sepharose affinity chromatography and eluted with 1 mM EGTA, there were two major polypeptides 120,000 and 67,000 daltons and at least three minor species (100,000, 60,000 and 40,000 daltons). The interaction required an active Ca2+-CaM complex and is specific for CaM. Double fluorescent staining with CaM-RITC and fluorescein-labeled antibodies to tubulin and DNAase I revealed a mitochondrial distribution pattern similar to that of microtubule arrays but unrelated to actin cabling. There was no evidence that CaM-RITC directly interacted with either microtubules or microfilaments.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Calcium-Binding Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Calmodulin,
http://linkedlifedata.com/resource/pubmed/chemical/Calmodulin-Binding Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Carrier Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Parvalbumins,
http://linkedlifedata.com/resource/pubmed/chemical/Troponin,
http://linkedlifedata.com/resource/pubmed/chemical/Troponin C
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pubmed:status |
MEDLINE
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pubmed:month |
Feb
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pubmed:issn |
0092-8674
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
23
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
533-42
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:7193532-Animals,
pubmed-meshheading:7193532-Binding Sites,
pubmed-meshheading:7193532-Calcium-Binding Proteins,
pubmed-meshheading:7193532-Calmodulin,
pubmed-meshheading:7193532-Calmodulin-Binding Proteins,
pubmed-meshheading:7193532-Carrier Proteins,
pubmed-meshheading:7193532-Cell Line,
pubmed-meshheading:7193532-Cytoskeleton,
pubmed-meshheading:7193532-Mice,
pubmed-meshheading:7193532-Microtubules,
pubmed-meshheading:7193532-Mitochondria,
pubmed-meshheading:7193532-Mitochondria, Liver,
pubmed-meshheading:7193532-Molecular Weight,
pubmed-meshheading:7193532-Parvalbumins,
pubmed-meshheading:7193532-Rats,
pubmed-meshheading:7193532-Troponin,
pubmed-meshheading:7193532-Troponin C
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pubmed:year |
1981
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pubmed:articleTitle |
The identification of calmodulin-binding sites on mitochondria in cultured 3T3 cells.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
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