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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
23
|
| pubmed:dateCreated |
1996-8-26
|
| pubmed:abstractText |
We have examined the role of conserved regions and acidic or basic residues located in the putative transmembrane segments of the cardiac sarcolemmal Na+-Ca2+ exchanger by site-directed mutagenesis. The alpha-1 and alpha-2 repeats are transmembrane regions of internal similarity, which are highly conserved among Na+-Ca2+ exchangers. We find that Na+-Ca2+ exchange activity is highly sensitive to mutagenesis in the alpha-repeats. Mutation at residues Ser-109, Ser-110, Glu-113, Ser-139, Asn-143, Thr-810, Ser-811, Asp-814, Ser-818, or Ser-838 resulted in loss of exchanger activity. Mutation at residues Thr-103, Gly-108, Pro-112, Glu-120, Gly-138, Gly-809, Gly-837, and Asn-842 resulted in reduced exchanger activity, and altered current-voltage relationships were observed with mutations at residues Gly-138 and Gly-837. Only mutation at residue Ser-117 appeared to leave exchanger activity unaffected. Thus, the alpha-repeats appear to be important components for ion binding and translocation. Another region implicated in exchanger function is a region of similarity to the Na+,K+ pump (Nicoll, D. A., Longoni, S., Philipson, K. D. (1990) Science 250, 562-565). Mutations at two residues in the pump-like region, Glu-199 and Thr-203, resulted in nonfunctional exchangers, while mutation at two other residues, Glu-196 and Gly-200, had no effect. The role of acidic and basic residues in the transmembrane segments was also examined. Mutation of several basic residues (Arg-42, His-744, Lys-751, Lys-797, and His-858) did not affect exchange activity. Of the acidic residues located outside of the alpha-repeat and pump-like regions (Asp-740, Asp-785, and Asp-798), only mutation at Asp-785 resulted in reduction of exchanger activity.
|
| pubmed:grant | |
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Calcium,
http://linkedlifedata.com/resource/pubmed/chemical/Carrier Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Sodium,
http://linkedlifedata.com/resource/pubmed/chemical/Sodium-Calcium Exchanger,
http://linkedlifedata.com/resource/pubmed/chemical/Sodium-Potassium-Exchanging ATPase
|
| pubmed:status |
MEDLINE
|
| pubmed:month |
Jun
|
| pubmed:issn |
0021-9258
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
7
|
| pubmed:volume |
271
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
13385-91
|
| pubmed:dateRevised |
2007-11-15
|
| pubmed:meshHeading |
pubmed-meshheading:8662775-Amino Acid Sequence,
pubmed-meshheading:8662775-Animals,
pubmed-meshheading:8662775-Binding Sites,
pubmed-meshheading:8662775-Calcium,
pubmed-meshheading:8662775-Carrier Proteins,
pubmed-meshheading:8662775-Cell Membrane,
pubmed-meshheading:8662775-Conserved Sequence,
pubmed-meshheading:8662775-Models, Molecular,
pubmed-meshheading:8662775-Molecular Sequence Data,
pubmed-meshheading:8662775-Mutagenesis, Site-Directed,
pubmed-meshheading:8662775-Myocardium,
pubmed-meshheading:8662775-Point Mutation,
pubmed-meshheading:8662775-Repetitive Sequences, Nucleic Acid,
pubmed-meshheading:8662775-Sarcolemma,
pubmed-meshheading:8662775-Sequence Homology, Amino Acid,
pubmed-meshheading:8662775-Sodium,
pubmed-meshheading:8662775-Sodium-Calcium Exchanger,
pubmed-meshheading:8662775-Sodium-Potassium-Exchanging ATPase
|
| pubmed:year |
1996
|
| pubmed:articleTitle |
Mutation of amino acid residues in the putative transmembrane segments of the cardiac sarcolemmal Na+-Ca2+ exchanger.
|
| pubmed:affiliation |
Department of Physiology, UCLA, School of Medicine, Los Angeles, California 90095-1760, USA.
|
| pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
|