Interleukin-1 activates p54 mitogen-activated protein (MAP) kinase/stress-activated protein kinase by a pathway that is independent of p21ras, Raf-1, and MAP kinase kinase.

摘要: In KB epidermoid cells, we previously showed that interleukin-1 alpha (IL-1) and various mitogens activate the mitogen-activated protein (MAP) kinases ERK1 ERK2, which phosphorylate both myelin basic (MBP) a peptide containing Thr669 of epidermal growth factor receptor. cell-free extracts made from gingival fibroblasts treated with platelet-derived or HepG2 hepatoma cells stimulated phorbol myristate acetate, MBP kinase were elevated 4-fold, ERK2 tyrosine-phosphorylated. these IL-1 activated kinase(s) phosphorylated but not failed to cause tyrosine phosphorylation ERK1/ERK2. Ceramide has been proposed as an intracellular mediator action, C2-ceramide sphingosine predominantly MBP-specific activity in had no effect cells. p54 MAP (also called stress-activated kinase) is c-Jun first isolated livers cycloheximide-treated rats. After stimulation, immunoprecipitates lysates all three cell types specific anti-p54 serum contained phosphorylating activity, whereas precipitates unstimulated detectable activity. The major peak IL-1-stimulated co-chromatographed on Mono Q phenyl-Superose immunodetectable kinase. did p21ras activation any type. Induction Thr 669 was abrogated by elevation cAMP levels, shown interfere Raf-1. We could detect unfractionated small amount this it precipitated anti-Raf-1 antibody. conclude most IL-1-activated portion due its Ras-, Raf-, kinase-independent.