Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
21
pubmed:dateCreated
2005-11-2
pubmed:abstractText
The natriuretic peptide receptor-A (NPR-A) is composed of an extracellular ligand-binding domain, a transmembrane-spanning domain, a kinase homology domain (KHD) and a guanylyl cyclase domain. Because the presence of ATP or adenylylimidodiphosphate reduces atrial natriuretic peptide (ANP) binding and is required for maximal guanylyl cyclase activity, a direct interaction of ATP with the receptor KHD domain is plausible. Therefore, we investigated whether ATP interacts directly with a binding site on the receptor by analyzing the binding of a photoaffinity analog of ATP to membranes from human embryonic kidney 293 cells expressing the NPR-A receptor lacking the guanylyl cyclase moiety (DeltaGC). We demonstrate that this receptor (NPR-A-DeltaGC) can be directly labeled by 8-azido-3'-biotinyl-ATP and that labeling is highly increased following ANP treatment. The mutant receptor DeltaKC, which does not contain the KHD, is not labeled. Photoaffinity labeling of the NPR-A-DeltaGC is reduced by 50% in the presence of 550 microm ATP, and competition curve fitting studies indicate a Hill slope of 2.2, suggestive of cooperative binding. This approach demonstrates directly that the interaction of ANP with its receptor modulates the binding of ATP to the KHD, probably through a conformational change in the KHD. In turn, this conformational change is essential for maximal activity. In addition, the ATP analog, 8-azido-adenylylimidodiphosphate, inhibits guanylyl cyclase activity but increases ANP binding to the extracellular domain. These results suggest that the KHD regulates ANP binding and guanylyl cyclase activity independently.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
1742-464X
pubmed:author
pubmed:issnType
Print
pubmed:volume
272
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5572-83
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Atrial natriuretic peptide-dependent photolabeling of a regulatory ATP-binding site on the natriuretic peptide receptor-A.
pubmed:affiliation
Department of Pharmacology, Faculty of Medicine, Université de Montréal, Montréal, Québec, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't