Linked Life Data

17693413

Source:http://linkedlifedata.com/resource/pubmed/id/17693413

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
45
pubmed:dateCreated
2007-11-5
pubmed:abstractText
Skeletal muscle acidosis during exercise has long been thought to be a cause of fatigue, but recent studies have shown that acidosis maintains muscle excitability and opposes fatigue by decreasing the sarcolemmal chloride conductance. ClC-1 is the primary sarcolemmal chloride channel and has a clear role in controlling muscle excitability, but recombinant ClC-1 has been reported to be activated by acidosis. Following our recent finding that intracellular ATP inhibits ClC-1, we investigated here the interaction between pH and ATP regulation of ClC-1. We found that, in the absence of ATP, intracellular acidosis from pH 7.2 to 6.2 inhibited ClC-1 slightly by shifting the voltage dependence of common gating to more positive potentials, similar to the effect of ATP. Importantly, the effects of ATP and acidosis were cooperative, such that ATP greatly potentiated the effect of acidosis. Adenosine had a similar effect to ATP at pH 7.2, but acidosis did not potentiate this effect, indicating that the phosphates of ATP are important for this cooperativity, possibly due to electrostatic interactions with protonatable residues of ClC-1. A protonatable residue identified by molecular modeling, His-847, was found to be critical for both pH and ATP modulation and may be involved in such electrostatic interactions. These findings are now consistent with, and provide a molecular explanation for, acidosis opposing fatigue by decreasing the chloride conductance of skeletal muscle via inhibition of ClC-1. The modulation of ClC-1 by ATP is a key component of this molecular mechanism.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
9
pubmed:volume
282
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
32780-91
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Inhibition of skeletal muscle ClC-1 chloride channels by low intracellular pH and ATP.
pubmed:affiliation
St. Vincent's Institute, Fitzroy, Victoria 3065, Australia.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't