Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
2005-2-21
pubmed:abstractText
Two fragments of the C-terminal tail of the alpha(1) subunit (CT1, amino acids 1538-1692 and CT2, amino acids 1596-1692) of human cardiac L-type calcium channel (Ca(V)1.2) have been expressed, refolded, and purified. A single Ca(2+)-calmodulin binds to each fragment, and this interaction with Ca(2+)-calmodulin is required for proper folding of the fragment. Ca(2+)-calmodulin, bound to these fragments, is in a more extended conformation than calmodulin bound to a synthetic peptide representing the IQ motif, suggesting that either the conformation of the IQ sequence is different in the context of the longer fragment, or other sequences within CT2 contribute to the binding of calmodulin. NMR amide chemical shift perturbation mapping shows the backbone conformation of calmodulin is nearly identical when bound to CT1 and CT2, suggesting that amino acids 1538-1595 do not contribute to or alter calmodulin binding to amino acids 1596-1692 of Ca(V)1.2. The interaction with CT2 produces the greatest changes in the backbone amides of hydrophobic residues in the N-lobe and hydrophilic residues in the C-lobe of calmodulin and has a greater effect on residues located in Ca(2+) binding loops I and II in the N-lobe relative to loops III and IV in the C-lobe. In conclusion, Ca(2+)-calmodulin assumes a novel conformation when part of a complex with the C-terminal tail of the Ca(V)1.2 alpha(1) subunit that is not duplicated by synthetic peptides corresponding to the putative binding motifs.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
280
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7070-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Sites on calmodulin that interact with the C-terminal tail of Cav1.2 channel.
pubmed:affiliation
Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas 77030, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't