Linked Life Data

18971388

Source:http://linkedlifedata.com/resource/pubmed/id/18971388

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2009-1-5
pubmed:abstractText
Members of the Na+/Ca2+ exchanger (NCX) family are important regulators of cytosolic Ca2+ in myriad tissues and are highly conserved across a wide range of species. Three distinct NCX genes and numerous splice variants exist in mammals, many of which have been characterized in a variety of heterologous expression systems. Recently, however, we discovered a fourth NCX gene (NCX4), which is found exclusively in teleost, amphibian, and reptilian genomes. Zebrafish (Danio rerio) NCX4a encodes for a protein of 939 amino acids and shows a high degree of identity with known NCXs. Although knockdown of NCX4a activity in zebrafish embryos has been shown to alter left-right patterning, it has not been demonstrated that NCX4a functions as a NCX. In this study, we 1) demonstrated, for the first time, that this gene encodes for a novel NCX; 2) characterized the tissue distribution of zebrafish NCX4a; and 3) evaluated its kinetic and transport properties. While ubiquitously expressed, the highest levels of NCX4a expression occurred in the brain and eyes. NCX4a exhibits modest levels of Na+-dependent inactivation and requires much higher levels of regulatory Ca2+ to activate outward exchange currents. NCX4a also exhibited extremely fast recovery from Na+-dependent inactivation of outward currents, faster than any previously characterized wild-type exchanger. While this result suggests that the Na+-dependent inactive state of NCX4a is far less stable than in other NCX family members, this exchanger was still strongly inhibited by 2 microM exchanger inhibitory peptide. We demonstrated that a new putative member of the NCX gene family, NCX4a, encodes for a NCX with unique functional properties. These data will be useful in understanding the role that NCX4a plays in embryological development as well as in the adult, where it is expressed ubiquitously.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0363-6143
pubmed:author
pubmed:issnType
Print
pubmed:volume
296
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
C173-81
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Characterization of zebrafish (Danio rerio) NCX4: a novel NCX with distinct electrophysiological properties.
pubmed:affiliation
Molecular Cardiac Physiology Group, Biomedical Physiology and Kinesiology, Simon Fraser University, 8888 Univ. Dr., Burnaby, BC, Canada V5A 1S6.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't