Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1996-12-4
pubmed:databankReference
pubmed:abstractText
The Na(+)-Ca2+ exchanger from Drosophila was expressed in Xenopus and characterized electrophysiologically using the giant excised patch technique. This protein, termed Calx, shares 49% amino acid identity to the canine cardiac Na(+)-Ca2+ exchanger, NCX1. Calx exhibits properties similar to previously characterized Na(+)-Ca2+ exchangers including intracellular Na+ affinities, current-voltage relationships, and sensitivity to the peptide inhibitor, XIP. However, the Drosophila Na(+)-Ca2+ exchanger shows a completely opposite response to cytoplasmic Ca2+. Previously cloned Na(+)-Ca2+ exchangers (NCX1 and NCX2) are stimulated by cytoplasmic Ca2+ in the micromolar range (0.1-10 microM). This stimulation of exchange current is mediated by occupancy of a regulatory Ca2+ binding site separate from the Ca2+ transport site. In contrast, Calx is inhibited by cytoplasmic Ca2+ over this same concentration range. The inhibition of exchange current is evident for both forward and reverse modes of transport. The characteristics of the inhibition are consistent with the binding of Ca2+ at a regulatory site distinct from the transport site. These data provide a rational basis for subsequent structure-function studies targeting the intracellular Ca2+ regulatory mechanism.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0022-1295
pubmed:author
pubmed:issnType
Print
pubmed:volume
108
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
67-74
pubmed:dateRevised
2008-11-20
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Anomalous regulation of the Drosophila Na(+)-Ca2+ exchanger by Ca2+.
pubmed:affiliation
Department of Physiology, University of California at Los Angeles, School of Medicine 90095, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't