Linked Life Data

19776005

Source:http://linkedlifedata.com/resource/pubmed/id/19776005

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
49
pubmed:dateCreated
2009-11-30
pubmed:abstractText
The contractile phenotype of smooth muscle (SM) cells is controlled by serum response factor (SRF), which drives the expression of SM-specific genes including SM alpha-actin, SM22, and others. Myocardin is a cardiac and SM-restricted coactivator of SRF that is necessary for SM gene transcription. Growth factors inducing proliferation of SM cells inhibit SM gene transcription, in a manner dependent on the activation of extracellular signal-regulated kinases ERK1/2. In this study, we found that ERK1/2 phosphorylates mouse myocardin (isoform B) at four sites (Ser(812), Ser(859), Ser(866), and Thr(893)), all of which are located within the transactivation domain of myocardin. The single mutation of each site either to alanine or to aspartate has no effect on the ability of myocardin to activate SRF. However, the phosphomimetic mutation of all four sites to aspartate (4xD) significantly impairs activation of SRF by myocardin, whereas the phosphodeficient mutation of all four sites to alanine (4xA) has no effect. This translates to a reduced ability of the 4xD (but not of 4xA) mutant of myocardin to stimulate expression of SM alpha-actin and SM22, as assessed by corresponding promoter, mRNA, or protein assays. Furthermore, we found that phosphorylation of myocardin at these sites impairs its interaction with acetyltransferase, cAMP response element-binding protein-binding protein, which is known to promote the transcriptional activity of myocardin. In conclusion, we describe a novel mode of modulation of SM gene transcription by ERK1/2 through a direct phosphorylation of myocardin.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1083-351X
pubmed:author
pubmed:issnType
Electronic
pubmed:day
4
pubmed:volume
284
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
33789-94
pubmed:dateRevised
2011-3-3
pubmed:meshHeading
pubmed-meshheading:19776005-Amino Acid Sequence, pubmed-meshheading:19776005-Animals, pubmed-meshheading:19776005-CHO Cells, pubmed-meshheading:19776005-Cricetinae, pubmed-meshheading:19776005-Cricetulus, pubmed-meshheading:19776005-Cyclic AMP Response Element Modulator, pubmed-meshheading:19776005-Enzyme Activation, pubmed-meshheading:19776005-Extracellular Signal-Regulated MAP Kinases, pubmed-meshheading:19776005-Gene Expression Regulation, pubmed-meshheading:19776005-Mice, pubmed-meshheading:19776005-Mitogen-Activated Protein Kinase 3, pubmed-meshheading:19776005-Molecular Sequence Data, pubmed-meshheading:19776005-Muscle, Smooth, pubmed-meshheading:19776005-Nuclear Proteins, pubmed-meshheading:19776005-Phenotype, pubmed-meshheading:19776005-Phosphorylation, pubmed-meshheading:19776005-Sequence Homology, Amino Acid, pubmed-meshheading:19776005-Trans-Activators
pubmed:year
2009
pubmed:articleTitle
Phosphorylation of myocardin by extracellular signal-regulated kinase.
pubmed:affiliation
Department of Medicine, The University of Chicago, Chicago, Illinois 60637, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural