Cell-substratum attachment and cell surface hyaluronate of rous sarcoma virus-transformed chondrocytes

Abstract

Hyaluronate is associated with the cell surface of cultured Rous sarcoma virustransformed chondrocytes. Detachment of these cells from their substratum by a variety of reagents is accompanied by release of 75-100% of this hyaluronate into solution. Treatment of the cells with 200 U/ml protease-free Streptomyces hyaluronidase at 37°C causes release of >90% of the cell surface hyaluronate and complete cell detachment. Treatment with a lower concentration of Streptomyces hyaluronidase (30 U/ml) at 25°C or a corresponding activity of testicular hyaluronidase gives similar results, but only in the presence of 1 mM EGTA. Treatment with the lower activities of either hyaluronidase or with 1 mM EGTA alone releases only ∼45% of the cell surface hyaluronate and does not cause significant cell detachment. It is concluded that there are two populations of cell surface hyaluronate differing in their accessibility or their resistance to dissociation from other components of the cell surface. It is proposed that the less readily released fraction is located between the transformed chondrocyte surface and substratum and is necessary for their interaction. © 1980, Rockefeller University Press., All rights reserved.