The v-mos and c-Ha-ras oncoproteins exert similar effects on the pattern of protein synthesis.

The effects of the ras and the mos oncogene products on the pattern of newly synthesized proteins was investigated in NIH3T3 cell lines. A conditional expression system which allowed hormonal induction of the oncogenes was utilized to detect effects on the accumulation of oncoproteins by two dimensional gel electrophoresis of crude cell extracts. Strong and reproducible changes of protein synthesis following the expression of the ras and mos oncogenes were detected. Transiently induced synthesis of four proteins with a molecular mass of 23 kDa, 32 kDa, 35 kDa, and 47 kDa was observed. These changes were qualitatively indistinguishable in both, ras and mos oncogene expressing cells. This is in agreement with the notion that the two oncogene products act on a common signal transduction pathway. Serum mediated growth induction of quiescent NIH3T3 cells led to a different pattern of altered protein synthesis. We observed the transient alteration in the synthesis rates of three proteins with a molecular mass of 27 kDa, 47 kDa and 52 kDa. Only the 47 kDa protein was also subject to regulation by the oncoproteins. One of the proteins whose synthesis was strongly induced by the ras and mos oncogene products is also expressed by heat shock.