Decreased alkaline phosphatase in cells transformed by rous sarcoma virus

Chick embryo cells transformed by either of two strains of Rous sarcoma virus (Bryan high titer or Schmidt-Ruppin) have low levels of alkaline phosphatase activity compared with nontransformed chick embryo cells. Essentially no differences in acid phosphatase activity were observed between these transformed and nontransformed cells. A virus mutant, RSV-BH-Ta, induces temperature-dependent transformation in infected cells. At 41 degrees, the transformation-nonpermissive temperature, alkaline phosphatase activities were similar to those of chick embryo cells. Shifting these cells to 37 degrees resulted in a change to transformed morphology and a progressive loss of enzyme activity, requiring 18 to 24 hr to reach the level of transformed cells. Rat embryo cells transformed by murine sarcoma virus also contained lower alkaline phosphatase levels than did nontransformed cells. These observations suggest that decreased alkaline phosphatase activities may be a general property of transformed cells.