Electrophoretic Analysis of Membrane Glycoproteins in Normal and Polyoma Virus Transformed BHK21 Cells

Abstract

BHK₂₁ cells transformed by polyoma virus have been shown to release protein into the medium which is more glycosylated than that released by normal BHK₂₁ cells. Correspondingly the residual protein in all membrane fractions (particularly plasma and smooth reticulum membranes) has a lower degree of glycosylation in transformed cells. The glycoproteins in these fractions and in saline washes of normal and transformed cells have been compared by electrophoresis in acrylamide gels. The washes from transformed cells contain a component of molecular weight about 135,000 which is more highly glycosylated than the corresponding component of normal cells. The corresponding membrane fractions of transformed cells are much less glycosylated. It is suggested that transformation by polyoma virus is accompanied by defects in the synthesis or assembly into the membranes of a large component with a high aminosugar to amino acid content.