Linked Life Data

19723630

Source:http://linkedlifedata.com/resource/pubmed/id/19723630

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
44
pubmed:dateCreated
2009-10-26
pubmed:abstractText
By now, little is known on L-type calcium channel (LTCC) subunits expressed in mouse heart. We show that CaVbeta2 proteins are the major CaVbeta components of the LTCC in embryonic and adult mouse heart, but that in embryonic heart CaVbeta3 proteins are also detectable. At least two CaVbeta2 variants of approximately 68 and approximately 72 kDa are expressed. To identify the underlying CaVbeta2 variants, cDNA libraries were constructed from poly(A)(+) RNA isolated from hearts of 7-day-old and adult mice. Screening identified 60 independent CaVbeta2 cDNA clones coding for four types of CaVbeta2 proteins only differing in their 5' sequences. CaVbeta2-N1, -N4, and -N5 but not -N3 were identified in isolated cardiomyocytes by RT-PCR and were sufficient to reconstitute the CaVbeta2 protein pattern in vitro. Significant L-type Ca(2+) currents (I(Ca)) were recorded in HEK293 cells after co-expression of CaV1.2 and CaVbeta2. Current kinetics were determined by the type of CaVbeta2 protein, with the approximately 72-kDa CaVbeta2a-N1 shifting the activation of I(Ca) significantly to depolarizing potentials compared with the other CaVbeta2 variants. Inactivation of I(Ca) was accelerated by CaVbeta2a-N1 and -N4, which also lead to slower activation compared with CaVbeta2a-N3 and -N5. In summary, this study reveals the molecular LTCC composition in mouse heart and indicates that expression of various CaVbeta2 proteins may be used to adapt the properties of LTCCs to changing myocardial requirements during development and that CaVbeta2a-N1-induced changes of I(Ca) kinetics might be essential in embryonic heart.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1083-351X
pubmed:author
pubmed:issnType
Electronic
pubmed:day
30
pubmed:volume
284
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
30129-37
pubmed:dateRevised
2010-11-2
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Diversity and developmental expression of L-type calcium channel beta2 proteins and their influence on calcium current in murine heart.
pubmed:affiliation
Experimentelle und Klinische Pharmakologie und Toxikologie, Universität des Saarlandes, 66421 Homburg, Germany. sabine.link@uks.eu
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't