Potassium‐induced reverse transformation of cells infected with a temperature‐sensitive transformation mutant virus

Abstract

High potassium concentrations altered the morphology and the ability to grow in soft agar in 6m2 cells, a clone of rat kidney cells infected with a temperature-sensitive mutant of Moloney sarcoma virus. Approximately 60% of cells exhibited normal morphology in the presence of 94.8 mM potassium in isotonic medium at the temperature permissive for transformation, whereas 100% were normal at 72 mM potassium in hypertonic media. A significant reduction of growth in soft agar was also induced with these conditions. However, the synthesis ratio of virus-specified transforming protein to marker viral protein was not altered. Na+K+-ATPase might play a role in this reverse-transformation process.

Potassium inhibition of transforming protein P85gag‐mos and reversal of the transformed phenotype in 6m2 cells

“…Transmembrane potential alterations reflect changes in the intracellular K+, Na+ ratio as well as Na+, K+-ATPase activity (Cone and Tongier, 1971). A subsequent study showed that, like temperature shifting, high K + concentrations (50 mM KC1) also induced reverse transformation of 6m2 cells (Lai and Becker, 1985). K+-treated cells grown at 33°C exhibited the flat morphology and reduced soft-agar growth characteristics of cells grown at 39°C.…”