Linked Life Data

11278298

Source:http://linkedlifedata.com/resource/pubmed/id/11278298

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
23
pubmed:dateCreated
2001-6-4
pubmed:abstractText
Among the drugs that are known to relax the vascular smooth muscle and regulate other cellular functions, beta-adrenergic agonists and nitric oxide-containing compounds are some of the most effective ones. The mechanisms of these drugs are thought to lower agonist-induced intracellular [Ca(2+)] by increasing intracellular cAMP and cGMP, activating their respective protein kinases. However, the physiological targets of cyclic nucleotide-dependent protein kinases are not clear. The molecular basis for the regulation of intracellular Ca(2+) by signaling pathways coupled to cyclic nucleotides is not well defined. G-protein-activated phospholipase C (PLC-beta) catalyzes the hydrolysis of phosphatidylinositol 4,5-bisphosphates to generate diacylglycerol and inositol 1,4,5-triphosphate, leading to the activation of protein kinase C and the mobilization of intracellular Ca(2+). In this study, we shown that G-protein-activated PLC enzymes are the potential targets of cGMP-dependent protein kinases (PKG). PKG can directly phosphorylate PLC-beta2 and PLC-beta3 in vitro with purified proteins and in vivo with metabolic labeling. Phosphorylation of PLC-beta leads to the inhibition of G-protein-activated PLC-beta3 activity by 50-70% in COS-7 cell transfection assays. By using phosphopeptide mapping and site-directed mutagenesis, we further identified two key phosphorylation sites for the regulation of PLC-beta3 by PKG (Ser(26) and Ser(1105)). Mutation at these two sites (S26A and S1105A) of PLC-beta3 completely blocked the phosphorylation of PLC-beta3 protein catalyzed by PKG. Furthermore, mutation of these serine residues removed the inhibitory effect of PKG on the activation of the mutant PLC-beta3 proteins by G-protein subunits. Our results suggest a molecular mechanism for the regulation of G-protein-mediated intracellular [Ca(2+)] by the NO-cGMP-dependent signaling pathway.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
8
pubmed:volume
276
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
19770-7
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Phosphorylation and regulation of G-protein-activated phospholipase C-beta 3 by cGMP-dependent protein kinases.
pubmed:affiliation
Department of Medical Biochemistry and Genetics, Center for Cancer Biology and Nutrition, Institute of Biosciences and Technology, Texas A & M University System Health Science Center, Houston, Texas 77030, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't