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rdf:type |
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lifeskim:mentions |
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pubmed:issue |
5
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pubmed:dateCreated |
1998-12-4
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pubmed:abstractText |
The cardiac muscle sarcoplasmic reticulum Ca2+ release channel (ryanodine receptor) is a ligand-gated channel that is activated by micromolar cytoplasmic Ca2+ concentrations and inactivated by millimolar cytoplasmic Ca2+ concentrations. The effects of sarcoplasmic reticulum lumenal Ca2+ on the purified release channel were examined in single channel measurements using the planar lipid bilayer method. In the presence of caffeine and nanomolar cytosolic Ca2+ concentrations, lumenal-to-cytosolic Ca2+ fluxes >/=0.25 pA activated the channel. At the maximally activating cytosolic Ca2+ concentration of 4 microM, lumenal Ca2+ fluxes of 8 pA and greater caused a decline in channel activity. Lumenal Ca2+ fluxes primarily increased channel activity by increasing the duration of mean open times. Addition of the fast Ca2+-complexing buffer 1,2-bis(2-aminophenoxy)ethanetetraacetic acid (BAPTA) to the cytosolic side of the bilayer increased lumenal Ca2+-activated channel activities, suggesting that it lowered Ca2+ concentrations at cytosolic Ca2+-inactivating sites. Regulation of channel activities by lumenal Ca2+ could be also observed in the absence of caffeine and in the presence of 5 mM MgATP. These results suggest that lumenal Ca2+ can regulate cardiac Ca2+ release channel activity by passing through the open channel and binding to the channel's cytosolic Ca2+ activation and inactivation sites.
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pubmed:grant |
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pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-1279096,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-1315621,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-1551198,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-1642895,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-1848635,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-1984866,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-2184764,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-2412607,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-2434495,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-2925624,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-3158652,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-6312285,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-7473684,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-7506128,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-7516645,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-7554124,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-7719847,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-7730403,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-7819484,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-7929585,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-8175760,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-8182731,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-8387229,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-8411131,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-8531200,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-8603501,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-8662280,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-8744299,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-8781199,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-8785276,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-8842211,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-8847630,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-8913591,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-8943948,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-9085308,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-9085309,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-9096063,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-9234963,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-9284302,
http://linkedlifedata.com/resource/pubmed/commentcorrection/9788925-9458720
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/1,2-bis(2-aminophenoxy)ethane-N,N,N'...,
http://linkedlifedata.com/resource/pubmed/chemical/Adenosine Triphosphate,
http://linkedlifedata.com/resource/pubmed/chemical/Caffeine,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium Channels,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium-Binding Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Egtazic Acid,
http://linkedlifedata.com/resource/pubmed/chemical/Liposomes,
http://linkedlifedata.com/resource/pubmed/chemical/Magnesium,
http://linkedlifedata.com/resource/pubmed/chemical/Ryanodine Receptor Calcium Release...
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pubmed:status |
MEDLINE
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pubmed:month |
Nov
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pubmed:issn |
0006-3495
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:volume |
75
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
2302-12
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pubmed:dateRevised |
2009-11-18
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pubmed:meshHeading |
pubmed-meshheading:9788925-Adenosine Triphosphate,
pubmed-meshheading:9788925-Animals,
pubmed-meshheading:9788925-Caffeine,
pubmed-meshheading:9788925-Calcium,
pubmed-meshheading:9788925-Calcium Channels,
pubmed-meshheading:9788925-Calcium-Binding Proteins,
pubmed-meshheading:9788925-Dogs,
pubmed-meshheading:9788925-Egtazic Acid,
pubmed-meshheading:9788925-Electrophysiology,
pubmed-meshheading:9788925-Liposomes,
pubmed-meshheading:9788925-Magnesium,
pubmed-meshheading:9788925-Myocardium,
pubmed-meshheading:9788925-Ryanodine Receptor Calcium Release Channel,
pubmed-meshheading:9788925-Sarcoplasmic Reticulum
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pubmed:year |
1998
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pubmed:articleTitle |
Regulation of cardiac muscle Ca2+ release channel by sarcoplasmic reticulum lumenal Ca2+.
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pubmed:affiliation |
Department of Biochemistry & Biophysics, University of North Carolina, Chapel Hill, North Carolina 27599-7260, USA.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
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