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Signaling pathways mediated by the mitogen‐activated protein (MAP) kinase kinase/MAP kinase cascade
Author(s) -
Matsuda Satoshi,
Gotoh Yukiko,
Nishida Eisuke
Publication year - 1994
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 - 10.1002/jlb.56.5.548
Subject(s) - map kinase kinase kinase , mitogen activated protein kinase kinase , map2k7 , ask1 , c raf , cyclin dependent kinase 9 , mitogen activated protein kinase , biology , cyclin dependent kinase 2 , microbiology and biotechnology , mapk14 , protein kinase a , kinase
Mitogen‐activated protein (MAP) kinase and its direct activator, MAP kinase kinase (MAPKK), comprise the MAPKK/MAP kinase cascade, which may play a pivotal role in a variety of intracellular signal transduction pathways from yeast to human. Vertebrate MAPKK, a dual‐specificity kinase, is activated by serine phosphorylation catalyzed by upstream serine/threonine kinases, MAPKK kinases (MAPKK‐Ks). MAPKK is, on the other hand, threonine phosphorylated by MAP kinase, although a physiological role of this MAP kinase–mediated phosphorylation of MAPKK is unknown. Biochemical fractionation of extracts from Xenopus mature oocytes revealed two major and one minor peaks for the MAPKK‐K activity. One of the major peaks contained a proto‐oncogene product c‐Mos, while the other peaks did not. These observations, together with a recent finding that several MAPKK‐Ks such as Raf‐1 and MEKK may function within a cell, suggest a diversity of MAPKK‐Ks. A variety of extracellular signals converge at the MAPKK/MAP kinase cascade through different MAPKK‐Ks and elicit a wide spectrum of cellular responses. Therefore, mechanisms that control activation of the MAP kinase cascade temporally and spatially may be important for specification of cellular responses. J. Leukoc. Biol. 56: 548‐553; 1994.