Comparisons of major cell-surface proteins of normal and transformed cells

Transformation of the chick fibroblast surface has been studied in cells infected with Schmidt-Ruppin Rous sarcoma virus and the temperature-sensitive mutant of this virus, TS-68. Major findings following transformation induced by a shift from nonpermissive (41 C.) to permissive (36 C.) temperature in TS-68 infected cells were: (1) rapid cessation or slowing of the synthesis of a protein, M.W. 100-200,000, localization uncertain; (2) cessation or slowing of the synthesis of a plasma membrane protein, M.W. 45,000, within 2-4 hours; (3) cessation or slowing of the synthesis of a large trypsin- and collagenase- sensitive protein (M.W. greater than 200,000) only after an extended period of morphologic transformation. In addition, increased quantities of type-specific viral antigen in the membranes of infected cells were observed in TS-68-infected cells at 41 compared with 36 C.