Interaction of Fibroblasts, Hemopoietic Cells and Platelets with Extracellular Matrix: Characterization and Role of a Common Cell Surface Glycoproteina

Cell adhesion to the extracellular matrix plays an important role in the complex phenomena involving cell motility, such as tumor metastasis1 and embryonic development.2 Interaction with the extracellular matrix is also required for the proper cellular response to growth and differentiation factors.3 A number of extracellular glycoproteins, which include fibronectin, laminin, vitronectin and collagens, are able to protnote cell adhesion by interacting with the plasma membrane.4 The complex and dynamic process of cell adhesion requires that, after binding to the adhesive factor, receptors in the plasma membrane either cluster and participate in the formation of adhesion plaques that are necessary for stable adhesion, or otherwise interact with the cytoskeletal motor to activate the tractional forces necessary for cell locomotion.5 In the present paper we will briefiy summarize some of our past work and report some new data on the identification, structural characterization and functional role of a mouse membrane glycoprotein implicated in the adhesion of fibroblasts, hemopoietic cells and platelets to the extracellular matrix.