Open Access Green as soon as Postprint is submitted to ZB.
Protein kinase Cα activates RAF-1 by direct phosphorylation.
Nature 364, 249-252 (1993)
THE kinase Raf-1 can be activated by treatment of cells with mitogens and by the protein kinase C (PKC) activator 12-O-tetradecanoyl-phorbol-13-acetate (TPA) (reviewed in refs 1, 2). Activated Raf-1 triggers a protein kinase cascade by direct phosphorylation of MAP kinase kinase3-5, resulting in phosphorylation of ternary complex factor6 and Jun7,8 by MAP kinase. Here we investigate the molecular mechanism and biological consequences of PKCα-mediated Raf-1 activation in NIH3T3 fibroblasts. PKCα directly phosphorylates and activates Raf-1 both in vitro and in vivo. PKCα induces Raf-1 phosphorylation at several sites, including a serine residue at position 499. Mutation of serine at this position or at residue 259 does not abrogate Raf-1 stimulation by a combination of Ras plus the src tyrosine kinase Lck, but severely impedes Raf-1 activation by PKCα. Consistent with such a direct interaction is the observation that Raf-1 and PKCα cooperate in the transformation of NIH3T3 cells. The Ser499 phosphorylation site is necessary for this synergism.
Altmetric
Additional Metrics?
Edit extra informations
Login
Publication type
Article: Journal article
Document type
Scientific Article
ISSN (print) / ISBN
0028-0836
e-ISSN
1476-4687
Journal
Nature
Quellenangaben
Volume: 364,
Issue: 6434,
Pages: 249-252
Publisher
Nature Publishing Group
Publishing Place
London
Reviewing status
Peer reviewed