Induction by the Guanosine Analogue Oxanosine of Reversion toward the Normal Phenotype of K-ras-transformed Rat Kidney Cells

Oxanosine, a guanosine analogue antibiotic, altered the “transformed” morphology of rat kidney cells integrating a temperature-sensitive K- ras gene into “normal” morphology at 34°C, a permissive temperature. Oxanosine also increased the cellular content of fibronectin to the normal level. The cells under these conditions had lower levels of guanine nucleotides and unstable and less palmitylated M r 21,000 protein (K- ras gene product, referred to as p21). These changes in p21 were the same as those which occurred to p21 in the cells cultured in the absence of oxanosine at 39.5°C, a nonpermissive temperature.