Linked Life Data

12080077

Source:http://linkedlifedata.com/resource/pubmed/id/12080077

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
35
pubmed:dateCreated
2002-8-30
pubmed:abstractText
The novel protein kinase C (nPKC) isoforms are important regulators of human involucrin (hINV) gene expression during keratinocyte differentiation (Efimova, T., and Eckert, R. L. (2000) J. Biol. Chem. 275, 1601-1607). Although the regulatory mechanism involves mitogen-activated protein kinase (MAPK) activation, the role of individual MAPK isoforms has not been elucidated. We therefore examined the effects of individual nPKCs on MAPK activation. We observe unique changes whereby nPKC expression simultaneously increases p38 activity and decreases ERK1 and ERK2 activity. Although p38 alpha, p38 beta, and p38 delta are expressed in keratinocytes, only a single isoform, p38 delta, accounts for the increased p38 activity. Parallel studies indicate that this isoform is also activated by treatment with the keratinocyte regulatory agents, 12-O-tetradecanoylphorbol-13-acetate, calcium, and okadaic acid. These changes in MAPK activity are associated with increased C/EBP alpha transcription factor expression and DNA binding to the hINV promoter and increased hINV gene expression. Expression of PKC delta, PKC epsilon, or PKC eta causes a 10-fold increase in hINV promoter activity, whereas C/EBP alpha expression produces a 25-fold increase. However, simultaneous expression of both proteins causes a synergistic 100-fold increase in promoter activity. These responses are eliminated by the dominant-negative C/EBP isoform, GADD153, and are also inhibited by dominant-negative forms of Ras, MEKK1, MEK3, and p38. These results suggest that the nPKC isoforms produce a unique shift in MAPK activity via a Ras, MEKK1, MEK3 pathway, to increase p38 delta and inhibit ERK1/2 and ultimately increase C/EBP alpha binding to the hINV promoter and hINV gene expression.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
30
pubmed:volume
277
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
31753-60
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Novel protein kinase C isoforms regulate human keratinocyte differentiation by activating a p38 delta mitogen-activated protein kinase cascade that targets CCAAT/enhancer-binding protein alpha.
pubmed:affiliation
Case Western Reserve University School of Medicine, Department of Physiology and Biophysics, Cleveland, Ohio 44106-4970, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't