TI  - Activation of  <prot<prot>>mitogen-activated protein kinase</prot> kinase</prot>  by  <prot>v-Raf</prot>  in NIH 3T3
      cells and in vitro.
PG  - 1404-7
AB  - Mitogen-activated protein (MAP) kinases are 42- and 44-kD serine-threonine
      protein kinases that are activated by tyrosine and threonine
      phosphorylation in cells stimulated with mitogens and growth factors.  <prot>MAP
      kinase</prot>  and the protein kinase that activates it ( <prot>MAP kinase kinase</prot> ) were
      constitutively activated in NIH 3T3 cells infected with viruses containing
      either of two oncogenic forms (p35EC12, p3722W) of the <prot>c-Raf-1</prot> protein
      kinase. The  <prot>v-Raf</prot>  proteins purified from cells infected with EC12 or 22W
      viruses activated  <prot><prot>MAP kinase</prot> kinase</prot>  from skeletal muscle in vitro.
      Furthermore, a bacterially expressed <prot>v-Raf</prot> fusion protein (glutathione
      S-transferase-p3722W) also activated <prot><prot>MAP kinase</prot> kinase</prot> in vitro. These
      findings suggest that one function of  <prot>c-Raf-1</prot>  in mitogenic signaling is to
      phosphorylate and activate  <prot><prot>MAP kinase</prot> kinase</prot> .
AD  - Department of Internal Medicine, University of Virginia, Charlottesville
