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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
1992-12-21
pubmed:abstractText
The receptor for tumor-promoting phorbol esters has been shown to be the Ca+2/phospholipid dependent enzyme protein kinase C (PKC). There are two major groups of PKC, the conventional PKC isotypes alpha, beta I, beta II, gamma) and the novel Ca+2-independent PKC (delta, epsilon, zeta, eta). Phorbol esters previously have been demonstrated to increase human IFN-gamma gene expression after treatment of a murine T cell line (Cl 9) that has been transfected with human IFN-gamma genomic DNA. In contrast, treatment with Ca+2 ionophore alone or in combination with phorbol ester did not enhance IFN-gamma production in a synergistic manner above the level obtained with phorbol ester treatment alone. To determine whether the lack of effect of Ca+2 ionophore is due to a defect in PKC, we compared the level of PKC autophosphorylation in the mouse T cell line (Cl 9), a mouse epidermal cell line (JB6), and purified rat brain PKC by in vitro kinase assays. The results demonstrate that instead of the expected 80-kDa autophosphorylated PKC band seen in purified rat brain PKC or mouse JB6 cell lysates, only a novel 97-kDa Ca+2-independent phosphoprotein was observed in Cl 9 cells. To ascertain if there was any nucleic acid sequence similarity to PKC epsilon, we hybridized Cl 9 poly(A+) RNA with a cloned fragment of the PKC epsilon gene and observed two hybridizing RNA bands (4.4 and 4.0 kb). Our results suggest that the 97-kDa phosphoprotein is similar to, but not identical with, PKC epsilon and is the major PKC expressed in the Cl 9 murine T cell line. These data suggested that the 97-kDa PKC may be responsible for the induction of both the transfected human IFN-gamma gene and the endogenous murine IL-2R alpha-chain.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
149
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3542-9
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
The presence in a mouse T cell line of a 97-kDa protein kinase C (PKC) with characteristics similar to known members of the novel PKC subgroup and its possible role in lymphocyte gene expression.
pubmed:affiliation
Laboratory of Viral Carcinogenesis, NCI-FCRDC, Frederick, MD 21702-1201.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S.