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Involvement of PKA, PKC, and Ca 2 + in LPS‐activated expression of the chicken lysozyme gene
Author(s) -
Regenhard Petra,
Goethe Ralph,
Phivan Loc
Publication year - 2001
Publication title -
journal of leukocyte biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.819
H-Index - 191
eISSN - 1938-3673
pISSN - 0741-5400
DOI - 10.1189/jlb.69.4.651
Subject(s) - lysozyme , protein kinase c , forskolin , gene expression , biology , microbiology and biotechnology , creb , signal transduction , enhancer , protein kinase a , ionophore , phosphorylation , biochemistry , transcription factor , gene , receptor , membrane
The lysozyme gene is activated in myelomonocytic HD11 cells in response to LPS. In this study, we described the involvement of LPS‐activated signal transduction pathways in activation of the lysozyme gene. Pre‐treatment of HD11 cells with H‐89, H‐7, TMB‐8, or KN‐93 resulted in inhibition of the LPS‐enhanced lysozyme expression, suggesting that PKA, PKC, and Ca 2 + ‐dependent protein kinases participate in the LPS activation. CaMKII seems to be required for the processing of lysozyme transcripts. TPA and calcium ionophore A23187, when separately added to HD11 cells, stimulated the lysozyme expression effectively, and forskolin was ineffective. It is interesting that simultaneous treatment of cells with forskolin and calcium ionophore A23187 resulted in a potentiated increase in lysozyme mRNA expression, indicating a synergistic cooperation of PKA and Ca 2 + . This synergistic effect of PKA and Ca 2 + was observed on the expression of a stably integrated CAT construct, controlled by the lysozyme promoter and the −6.1‐kb enhancer containing binding sites for C/EBP and NF‐κB/Rel. Therefore, we discussed the role of C/EBPβ(NF‐M), CREB, and NF‐κB/Rel as possible targets for phosphorylation mediated by PKA, PKC, and Ca 2 + .