Inactivation of Icmt inhibits transformation by oncogenic K-Ras and B-Raf
J. Clin. Invest. Martin O. Bergo, et al. 113:539 doi:10.1172/JCI18829 [Go to this article.]

Figure 1
Generation and validation of a conditional Icmt allele (Icmt^flx). (a) A sequence-replacement gene-targeting vector designed to flank exon 1 and upstream sequences with loxP sites. tk, thymidine kinase. (b) Southern blot identification of the Icmt⁺, Icmt^flx, and Icmt^Δ alleles with BamHI-cleaved genomic DNA and the 5′-flanking probe. (c) Icmt activity in extracts of Icmt^flx/flx and Icmt^Δ/Δ fibroblasts, as judged by a base-hydrolysis vapor-diffusion assay. Assays used S-adenosyl-L-[methyl-¹⁴C]methionine as the methyl donor and either farnesyl-K-Ras or N-acetyl-S-geranylgeranyl-L-cysteine (AGGC) as substrates. Bar graphs show the mean of two independent cell lines in two independent experiments. (d) Accumulation of Icmt substrates in Icmt^Δ/Δ cells. Recombinant yeast Ste14p was added to extracts of Icmt^flx/flx and Icmt^Δ/Δ cells along with S-adenosyl-L-[methyl-¹⁴C]methionine; methylation of protein substrates was measured with the base-hydrolysis vapor-diffusion assay.