Modification of the Calcium-Independent Mechanism of Cell Adhesion in Transformed BHK Cells

Abstract

The calcium-independent mechanism of cell adhesion was studied in normal and polyoma virus-transformed BHK cells. The degree of Ca²⁺-independent adhesion was greatly reduced in pyBHK cells, whereas Ca²⁺-dependent adhesion occurred to the same degree as in BHK cells. This decrease was shown not to be caused by simple masking of the adhesion sites or by their altered sensitivity to trypsin.
Adhesion-blocking antibodies were used to identify molecules responsible for Ca²⁺-independent adhesion. The antibodies precipitated surface molecules specific for adhesion-competent cells. These have tentatively been named CIDS_BHK and CIDS_pyBHK. Both were glycoproteins with respective apparent molecular weights of 120K and 125K. CIDS_pyBHK incorporated ³H-glucosamine more than CIDS_BHK did. Possible modification of the Ca²⁺-independent adhesion mechanism in pyBHK cells is discussed.