Cellular transformation and differentiation. Effect of Rous sarcoma virus transformation on sulfated proteoglycan synthesis by chicken chondrocytes.

Incorporation of sulfate into sulfated proteoglycans by isolated chicken chondrocytes was inhibited up to 74% by transformation with the Rous sarcoma virus, and a similar inhibitory effect was observed on acetate incorporation into chondroitin sulfate. Slower sedimenting sulfated proteoglycans appear after the viral transformation. The ratio of chondroitin 4-sulfate to chondroitin 6-sulfate in these slower sedimenting sulfated proteoglycans was different from that of normal chondrocytes, but the chain lengths of sulfated glycosaminoglycans produced by normal chondrocytes and transformed chondrocytes were not significantly different. Chondrocytes were also infected with a temperature-sensitive mutant of RSV, ts LA24, which has a temperature-sensitive lesion in the transforming gene. Hyaluronic acid production by these cells was increased, and the slower sedimenting sulfated proteoglycan was produced only at the permissive temperature.