H. Enslen, J. Raingeaud, R. Davis
Jan 16, 1998
The Journal of Biological Chemistry
The cellular response to treatment with proinflammatory cytokines or exposure to environmental stress is mediated, in part, by the p38 group of mitogen-activated protein (MAP) kinases. We report the molecular cloning of a novel isoform of p38 MAP kinase, p38β2. This p38 MAP kinase, like p38α, is inhibited by the pyridinyl imidazole drug SB203580. The p38 MAP kinase kinase MKK6 is identified as a common activator of p38α, p38β2, and p38γ MAP kinase isoforms, while MKK3 activates only p38α and p38γ MAP kinase isoforms. The MKK3 and MKK6 signal transduction pathways are therefore coupled to distinct, but overlapping, groups of p38 MAP kinases.