Document Detail


cAMP-dependent phosphorylation of the cardiac L-type Ca channel: a missing link?
MedLine Citation:
PMID:  8834778     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Cardiac inotropic effects of beta adrenergic agonists occur mainly through an increase in L-type (class C) calcium channel activity. This response has been attributed to phosphorylation of the L-type Ca channel, or a closely associated protein, by the cAMP-dependent protein kinase A (PKA). Among the three subunits forming the cardiac L-type Ca channel (alpha 1, beta and alpha 2-delta), biochemical studies have revealed that two subunits, alpha 1 and beta, are phosphorylated in vitro by protein kinase A, the alpha 1 subunit being the primary target. However, attempts to reconstitute the cAMP-dependent regulation of the expressed class C Ca channel, either in Xenopus oocytes or in cell lines, have provided contradictory results. We were unable to detect cAMP-dependent modulation of class C alpha 1 subunit Ca channels expressed in Xenopus oocytes, even when coinjected with auxiliary subunits beta and alpha 2-delta. Nevertheless, activity of Ca channels recorded from cardiac-mRNA injected oocytes was potentiated by injection of cAMP or PKA, even when expression of the beta subunit was suppressed using antisense oligonucleotide. Taken together, these results indicate that cAMP-dependent regulation does not exclusively involve the alpha 1 and the beta subunits of the Ca channel and suggest that unidentified protein(s), expressed in cardiac tissue, are most likely necessary.
Authors:
P Charnet; P Lory; E Bourinet; T Collin; J Nargeot
Related Documents :
10733968 - Gating of amiloride-sensitive na(+) channels: subunit-subunit interactions and inhibiti...
7719708 - Distinctive functional properties of the neuronal bii (class e) calcium channel.
16979758 - Signature combinatorial splicing profiles of rat cardiac- and smooth-muscle cav1.2 chan...
19413888 - The alpha1h ca2+ channel subunit is expressed in mouse jejunal interstitial cells of ca...
11430808 - Spike-associated fast contraction of dendritic spines in cultured hippocampal neurons.
7447048 - Adenosinetriphosphate (atp) in human spermatozoa. ii. concentrations in fertile men.
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Review    
Journal Detail:
Title:  Biochimie     Volume:  77     ISSN:  0300-9084     ISO Abbreviation:  Biochimie     Publication Date:  1995  
Date Detail:
Created Date:  1996-12-05     Completed Date:  1996-12-05     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  1264604     Medline TA:  Biochimie     Country:  FRANCE    
Other Details:
Languages:  eng     Pagination:  957-62     Citation Subset:  IM    
Affiliation:
Centre de Recherche de Biochimie Macromoléculaire, CNRS UPR 9008, INSERM U249, Montpellier, France.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Animals
Calcium Channels / metabolism*
Cyclic AMP / metabolism*
Cyclic AMP-Dependent Protein Kinases / metabolism
Humans
Myocardium / cytology,  metabolism
Phosphorylation
Receptors, Adrenergic, beta / metabolism*
Xenopus
Chemical
Reg. No./Substance:
0/Calcium Channels; 0/Receptors, Adrenergic, beta; 60-92-4/Cyclic AMP; EC 2.7.11.11/Cyclic AMP-Dependent Protein Kinases

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Conformational changes of active sites during refolding of urea-denatured creatine kinase.
Next Document:  Growth phase and growth rate dependence of ribosomal peptidyltransferase activity status in Escheric...