Linked Life Data

12502530

Source:http://linkedlifedata.com/resource/pubmed/id/12502530

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
2002-12-27
pubmed:abstractText
The membrane domain of the Na(+)/Ca(2+) exchanger (NCX) contains two conserved internal repeat sequences, designated the alpha-1 and alpha-2 repeats. We have studied the topological disposition of residues in the alpha repeats and a neighboring region by substituted cysteine accessibility scanning as well as the functional importance of these residues by kinetically evaluating transport activities of cysteine-substituted or other site-directed NCX1 mutants. The results suggest that the alpha-1 repeat contains a reentrant loop originating from extracellular side of the membrane, while the alpha-2 repeat and its neighboring region contain a complex reentrant loop structure originating from the cytoplasmic side. We identified several residues in the alpha-1 repeat loop whose mutation caused significant alterations in the interaction of NCX1 with a transport substrate Ca(2+)(o) and inhibitory ions Ni(2+) and Co(2+). On the other hand, we found residues in the alpha-2 repeat loop region whose mutation altered the interaction with an activating ion Li(+) and an inhibitory drug KB-R7943 in addition to the effect on Ca(2+)(o) and Ni(2+). Collectively, our data suggest that these alpha-repeat regions participate in the formation of ion translocation pathway of the exchanger and that the alpha-1 repeat loop plays an important role in ion selection.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0077-8923
pubmed:author
pubmed:issnType
Print
pubmed:volume
976
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
19-30
pubmed:dateRevised
2006-10-19
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Probing ion binding sites in the Na+/Ca2+ exchanger.
pubmed:affiliation
Department of Molecular Physiology, National Cardiovascular Center Research Institute, Suita, Osaka 565-8565, Japan. shigekaw@ri.ncvc.go.jp
pubmed:publicationType
Journal Article, Review