Figure 1.

Alterations in prenylation pattern are a specific marker of active K-ras. (A) The pattern of [³H]-MVA-labeled proteins in FRTL-5 and KiMol cells, in cells derived from a thyroid carcinoma (TK-6) and lung metastates (MPTK-6) by the injection of v-K-ras, and in H-ras-transformed FRTL-5 cells. KiMol-labeled proteins were immunoprecipitated with an anti-p21^ras mAb and nonspecific immunoserum. (B) Electrophoretic profile (left) and densitometric analysis (right) of the major proteins (p48 and p21) in FRTL-5 cells transformed with the temperature-sensitive mutant v-K-ras (Ats) at 39°C and in the same cells shifted to 33°C for 1, 3, and 7 days. Cells were incubated with [³H]-MVA (30 Ci/mmol) for 7 hr in the presence of 10 μM lovastatin and were processed as described in Experimental Procedures. Protein extracts were analyzed by 12% SDS/PAGE and fluorography. Molecular weight standards are shown on the right. These data are representative of four independent experiments. The autoradiogram was exposed for 20 days.