Ha-ras stimulates the transplasma membrane oxidoreductase activity of C3H10T1/2 cells.

The ras family of oncogenes, as well as the transplasma membrane electron transport system, have been implicated in cellular growth control. Here we present evidence that the Ha-ras oncoprotein increases the activity of the transplasma membrane electron transport system in the mouse embryonic fibroblast cell line C3H10T1/2. Both cytochrome c and ferricyanide are reduced at a faster rate by C3H10T1/2 cells which are expressing the Ha-ras oncogene. In addition, the Ha-ras transformed cells extrude protons faster in response to stimulation by external oxidants than their normal counterparts. These results suggest that transformation events initiated by the expression of the Ha-ras oncoprotein, p21, in C3H10T1/2 cells have a controlling effect on the transplasma membrane electron transport system.