Endotoxin-induced cytokine gene transcription in monocytes and macrophages is regulated in part by NF-B. We have previously shown that the p38 mitogenactivated protein (MAP) kinase is necessary for endotoxin-induced cytokine gene transcription. Due to the fact that most cytokine promoter sequences have active NF-B sites, we hypothesized that the p38 MAP kinase was necessary for NF-B-dependent gene expression. We found that NF-B-dependent gene expression was reduced to near control levels with either SB 203580 or a dominant-negative p38 MAP kinase expression vector. Inhibition of the p38 MAP kinase did not alter NF-B activation at any level, but it significantly reduced the DNA binding of TATA-binding protein (TBP) to the TATA box. The dominant-negative p38 MAP kinase expression vector interfered with the direct interaction of native TFIID (TBP) with a co-transfected p65 fusion protein. Likewise, this dominant-negative plasmid also interfered with the direct interaction of a co-transfected TBP fusion protein with the native p65 subunit. The p38 kinase also phosphorylated TFIID (TBP) in vitro, and SB 203580 inhibited phosphorylation of TFIID (TBP) in vivo. Thus, the p38 MAP kinase regulates NF-B-dependent gene transcription, in part, by modulating activation of TFIID (TBP). Cytokine gene expression in endotoxin (LPS)1 -stimulated macrophages is regulated, at least in part, at the level of transcription. A transcription factor that is necessary for the transcription of many cytokine genes is nuclear factor B (NF-B) (1-4). In addition to others, we have previously shown that NF-B binds to specific cytokine promoter sequences (1-8). NF-B is composed of heterodimers (most commonly p50 and p65) of members of the Rel family of transcription factors. In quiescent cells the heterodimers are kept in the cytoplasm by an inhibitor protein, IB (9 -11). NF-B translocation and DNA binding is dependent on IB kinase (IKK), which phosphorylates IB on serines within the amino-terminal domain (12)(13)(14)(15)(16)(17). This phosphorylation results in IB degradation, thus allowing NF-B translocation to the nucleus. Other factors, however, have been shown to be essential for NF-B transcriptional activation, especially phosphorylation of the p65 subunit of NF-B in one of two of its transactivation domains (18). In addition, the association of the carboxyl terminus of p65 with basal transcription factors, such as transcription factor IIB (TFIIB) and TATA-binding protein (TBP), is known to be important for transcriptional regulation of .One family of kinases that is essential for transferring signals from the cell surface to the nucleus is the mitogen-activated protein (MAP) kinases. We and others have shown that the p38 MAP kinase is critical for LPS-induced cytokine gene expression (23)(24)(25)(26).Some of these studies showed that LPS, interleukin 1, and osmotic stress activate p38 MAP kinases, and inhibition with SB 203580, a competitive inhibitor of the p38 MAP kinases, reduced cytokine release but did not affect cytokine mRNA accumu...

Background-Mitogen activated protein (MAP) kinases and nuclear factor kappa-B (NF-κB) are implicated in early stages of acute pancreatitis pathogenesis. We investigated the relationship between the p38 MAP kinase and NF-κB in isolated acinar cells.