Geranylgeranylated RhoB is sufficient to mediate tissue-specific suppression of Akt kinase activity by farnesyltransferase inhibitors

Farnesyltransferase inhibitors (FTIs) induce apoptosis by elevating the lev els of geranylgeranylated RhoB (RhoB-GG) in cells, However, the mechanism b y which RhoB-GG acts is unclear. Here we report that RhoB-GG is sufficient to mediate the suppressive effects of FTIs on the activity of the survival kinase Akt-1 in epithelial cells, This mechanism is tissue-specific insofar as it does not operate in fibroblasts. We discuss how the cell survival fu nctions of RhoB and Akt may be linked biochemically in certain cell types, (C) 2000 Federation of European Biochemical Societies. Published by Elsevie r Science B.V. All rights reserved.