Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
51
pubmed:dateCreated
2001-1-8
pubmed:abstractText
Neuronal voltage-dependent Ca(2+) channels of the N (alpha(1B)) and P/Q (alpha(1A)) type are inhibited by neurotransmitters that activate G(i/o) G proteins; a major part of the inhibition is voltage-dependent, relieved by depolarization, and results from a direct binding of Gbetagamma subunit of G proteins to the channel. Since cardiac and neuronal L-type (alpha(1C)) voltage-dependent Ca(2+) channels are not modulated in this way, they are presumed to lack interaction with Gbetagamma. However, here we demonstrate that both Gbetagamma and calmodulin directly bind to cytosolic N and C termini of the alpha(1C) subunit. Coexpression of Gbetagamma reduces the current via the L-type channels. The inhibition depends on the presence of calmodulin, occurs at basal cellular levels of Ca(2+), and is eliminated by EGTA. The N and C termini of alpha(1C) appear to serve as partially independent but interacting inhibitory gates. Deletion of the N terminus or of the distal half of the C terminus eliminates the inhibitory effect of Gbetagamma. Deletion of the N terminus profoundly impairs the Ca(2+)/calmodulin-dependent inactivation. We propose that Gbetagamma and calmodulin regulate the L-type Ca(2+) channel in a concerted manner via a molecular inhibitory scaffold formed by N and C termini of alpha(1C).
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
22
pubmed:volume
275
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
39846-54
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Modulation of L-type Ca2+ channels by gbeta gamma and calmodulin via interactions with N and C termini of alpha 1C.
pubmed:affiliation
Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Ramat Aviv 69978, Israel.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't