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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1998-12-14
pubmed:abstractText
Epidermal growth factor (EGF) has been found to induce enhanced gap junctional intercellular communication (GJIC) in the human kidney epithelial cell line K7. This is in contrast to what is reported for other cell types, which all show decreased GJIC in response to EGF. In the present study it is shown that 12-O-tetradecanoylphorbol-13-acetate (TPA) and EGF induce similar phosphorylation pattern of the gap junction protein connexin43 (Cx43) in K7 cells, although their effects on GJIC are opposite. Tyrosine phosphorylation of a 42 kD protein was observed to be induced concomitantly with phosphorylation of Cx43. EGF was however found to induce only serine phosphorylation of Cx43, indicating that the tyrosine kinase activity of the EGF receptor was not directly affecting the gap junction protein. The 42 kD protein phosphorylated on tyrosine was identified to be a mitogen activated protein (MAP) kinase. Both EGF and TPA was found to activate MAP kinase in these cells. Phosphorylation of Cx43 and enhancement of GJIC in response to EGF occurred with difference in time course. Phosphorylation of Cx43 was completed within 15 min, while the enhanced GJIC appeared 2-3 h later. It is therefore possible that regulation of synthesis or transport of Cx43 is responsible for the increase in GJIC, rather than direct involvement of Cx43 phosphorylation. This is in support of our previous finding that protein synthesis is necessary for EGF induced upregulation of GJIC in K7 cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1061-5385
pubmed:author
pubmed:issnType
Print
pubmed:volume
5
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
451-60
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed-meshheading:9791726-Antibodies, pubmed-meshheading:9791726-Blotting, Western, pubmed-meshheading:9791726-Calcium-Calmodulin-Dependent Protein Kinases, pubmed-meshheading:9791726-Cell Communication, pubmed-meshheading:9791726-Cell Line, pubmed-meshheading:9791726-Connexin 43, pubmed-meshheading:9791726-Enzyme Activation, pubmed-meshheading:9791726-Epidermal Growth Factor, pubmed-meshheading:9791726-Epithelial Cells, pubmed-meshheading:9791726-Gap Junctions, pubmed-meshheading:9791726-Humans, pubmed-meshheading:9791726-Kidney, pubmed-meshheading:9791726-Phosphoproteins, pubmed-meshheading:9791726-Phosphorylation, pubmed-meshheading:9791726-Phosphoserine, pubmed-meshheading:9791726-Phosphotyrosine, pubmed-meshheading:9791726-Precipitin Tests, pubmed-meshheading:9791726-Tetradecanoylphorbol Acetate, pubmed-meshheading:9791726-Time Factors
pubmed:year
1998
pubmed:articleTitle
Role of Cx43 phosphorylation and MAP kinase activation in EGF induced enhancement of cell communication in human kidney epithelial cells.
pubmed:affiliation
Department of Environmental and Occupational Cancer, Norwegian Radium Hospital, Oslo, Norway.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't