COORDINATE CONTROL OF COLLAGEN-SYNTHESIS AND CELL-GROWTH IN CHICK-EMBRYO FIBROBLASTS AND EFFECT OF VIRAL TRANSFORMATION ON COLLAGEN-SYNTHESIS

Using collagenase digestion as an assay for collagen in partially synchronized secondary cultures of chick embryo fibroblasts indicated that the rate of collagen synthesis remains at a constant fraction of overall protein synthesis (5%) regardless of the growth rate of the cells, even when the rate of protein synthesis is accelerated 5-fold by adding serum and altering the pH of the culture medium. In cells oncogenically transformed by Rous sarcoma virus [RSV], the relative rate of collagen synthesis was decreased by 50% 24 h after infection and was 10% of the initial rate after 5 days. This selective decrease in rate of collagen synthesis could be reversed in cells infected with an RSV temperature-sensitive transformation-defective mutant at the non-permissive temperature, indicating that the decrease in the rate of collagen synthesis was not merely the result of viral infection but was a direct consequence of oncogenic transformation.