The Farnesyl Group of H-Ras Facilitates the Activation of a Soluble Upstream Activator of Mitogen-activated Protein Kinase (∗)

• Published in: The Journal of biological chemistry 1995-11, Vol.270 (44), p.26347-26351
• Main Authors: McGeady, Paul, Kuroda, Shinya, Shimizu, Kazuya, Takai, Yoshimi, Gelb, Michael H.
• Format: Article
• Language: English
• Subjects: Animals; Calcium-Calmodulin-Dependent Protein Kinases - metabolism; Cell-Free System; Enzyme Activation; Female; Guanosine 5'-O-(3-Thiotriphosphate) - metabolism; Guanosine 5'-O-(3-Thiotriphosphate) - pharmacology; Kinetics; Myelin Basic Protein - metabolism; Oocytes - metabolism; Phosphorylation; Polyisoprenyl Phosphates - metabolism; Protein Prenylation; ras Proteins - metabolism; ras Proteins - pharmacology; Recombinant Proteins - metabolism; Recombinant Proteins - pharmacology; Sesquiterpenes; Xenopus laevis
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.270.44.26347

To study the function of the farnesyl modification of Ras, the farnesyl group and a variety of its structural analogs, which lack one or more double bonds and/or the methyl groups, were enzymatically incorporated into recombinant H-Ras in vitro. These proteins were used in a cell- and membrane-free, Ras-dependent mitogen-activated protein kinase (MAP kinase) activation system derived from Xenopus laevis eggs to examine the contribution of the farnesyl group toward the activation of the kinase. Whereas non-farnesylated H-Ras is unable to activate MAP kinase, farnesylation of H-Ras alone, in the absence of further processing, is sufficient to cause the activation of MAP kinase in this system. All of the analogs of the farnesyl group, when incorporated into H-Ras, support the activation of the kinase to variable extents. These results suggest a direct but fairly nonspecific interaction of the farnesyl moiety of H-Ras with a soluble upstream activator of MAP kinase.