Linked Life Data

2413367

Source:http://linkedlifedata.com/resource/pubmed/id/2413367

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6037
pubmed:dateCreated
1985-11-14
pubmed:abstractText
Binding of acetylcholine (ACh) to cardiac muscarinic ACh receptors (mAChR) activates a potassium channel that slows pacemaker activity. Although the time course of this activation suggests a multi-step process with intrinsic delays of 30-100 ms, no second-messenger system has been demonstrated to link the mAChR to the channel. Changes in cyclic nucleotide levels (cyclic AMP and cyclic GMP) do not affect this K channel or its response to muscarinic agonists. Indeed, electrophysiological experiments argue against the involvement of any second messenger that diffuses through the cytoplasm. We report here that coupling of the mAChR in embryonic chick atrial cells to this inward rectifying K channel requires intracellular GTP. Furthermore, pretreatment of cells with IAP (islet-activating protein from the bacterium Bordetella pertussis) eliminates the ACh-induced inward rectification. As IAP specifically ADP-ribosylates two GTP-binding proteins, Ni and No, that can interact with mAChRs, we conclude that a guanyl nucleotide-binding protein couples ACh binding to channel activation. This represents the first demonstration that a GTP-binding protein can regulate the function of an ionic channel without acting through cyclic nucleotide second messengers.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0028-0836
pubmed:author
pubmed:issnType
Print
pubmed:volume
317
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
536-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:articleTitle
GTP-binding proteins couple cardiac muscarinic receptors to a K channel.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't