The ERK, JNK/SAPK and p38/RK MAP kinase subtypes (reviewed in ) are differentially activated in mammalian cells by various stimuli, which elicit induction of immediate-early (IE) genes, such as c-fos and c-jun (reviewed in [1-3]), as well as phosphorylation of histone H3  and HMG-14 . Anisomycin and UV radiation have been suggested to induce c-fos and c-jun transcription via JNK/SAPK-mediated phosphorylation of TCF (ternary complex factor), for c-fos induction [6-8], and c-jun and/or ATF-2 for c-jun induction [9-13]. We report here that anisomycin and ultraviolet radiation (UV) activate MAP kinase kinase-6 (MKK6) [14,15], p38/RK [16-18] and MAPKAP kinase-2 (MAPKAP K-2) [17-19]. By using the p38/RK inhibitor SB 203580 [20,21], we show that activation of p38/RK and/or its downstream effectors are essential for anisomycin- and UV-stimulated c-fos/c-jun induction and histone H3/HMG-14 phosphorylation, whereas JNK/SAPK activation and phosphorylation of c-jun and ATF-2 are insufficient for these responses.
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Agricultural and Biological Sciences(all)