Functional characterization of antiadhesion molecules.

Cytotactin, cytotactin binding (CTB) proteoglycan, and several other extracellular matrix (ECM) proteins and proteoglycans are described as antiadhesion molecules because they inhibit cell spreading and attachment to normally permissive ECM proteins. For cytotactin and CTB proteoglycan, this effect appears to be due to the binding of these proteins to their cell-surface receptors, which initiates a transmembrane signal that inhibits cell spreading. In contrast, the binding of fibronectin or laminin to its cell-surface receptors promotes cell spreading.