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Publication

KSR stimulates Raf-1 activity in a kinase-independent manner.

Kinase suppressor of Ras (KSR) is an evolutionarily conserved component of Ras-dependent signaling pathways. Here, we find that murine KSR (mKSR1) translocates from the cytoplasm to the plasma membrane in the presence of activated Ras. At the membrane, mKSR1 modulates Ras signaling by enhancing Raf-1 activity in a kinase-independent manner. The activation of Raf-1 is mediated by the mKSR1 cysteine-rich CA3 domain and involves a detergent labile cofactor that is not ceramide. These findings reveal another point of regulation for Ras-mediated signal transduction and further define a noncatalytic role for mKSR1 in the multistep process of Raf-1 activation.

Publication date
November 25, 1997
Principal Investigators
Michaud NR, Therrien M, Cacace A, Edsall LC, Spiegel S, Rubin GM, Morrison DK
PubMed reference
Proc. Natl. Acad. Sci. U.S.A. 1997;94(24):12792-6
PubMed ID
9371754
Affiliation
Molecular Basis of Carcinogenesis Laboratory, National Cancer Institute, Frederick Cancer Research and Development Center, MD 21702, USA.