Levels of translatable mRNAs for cell surface protein, collagen precursors, and two membrane proteins are altered in Rous sarcoma virus-transformed chick embryo fibroblasts.

Abstract

Transformation of chick embryo fibroblasts by Rous sarcoma virus results in decreased amounts of a major cell surface protein and a collagen. To determine the mechanism accounting for the decreased production of these proteins, the relative amounts of functional mRNA for these and other transformation-sensitive proteins were measured. Total cellular RNA extracted from normal cells and from cells transformed by the Schmidt-Ruppin strain of Rous sarcoma virus were translated in a cell-free system derived form wheat germ. Analysis of the in vitro translation products of RNA from normal and transformed chick embryo fibroblasts shows a 5-fold reduction in the translatable mRNA for cell surface protein and a 10-fold reduction in translatable mRNA for 2 collagen precursors. Increases in functional mRNA are also observed for myosin and for 2 membrane polypeptides with MW of 95,000 and 78,000; the latter 2 proteins increase on transformation, but the increases are in large part secondary to the depletion of glucose from the medium of transformed cells. Some of the major cellular changes induced by oncogenic viruses are probably due to changes in the activity of specific cellular genes.