E-CADHERIN MEDIATED CELL-ADHESION RECRUITS SAP97 INTO THE CORTICAL CYTOSKELETON

Members of the SAP family of synapse-associated proteins have recently emerged as central players in the molecular organization of synapses. In this study, we have examined the mechanism that localizes one memb er, SAP97, to sites of cell-cell contact. Utilizing epithelial CACO-2 cells and fibroblast L-cells as model systems, we demonstrate that SAP 97 is associated with the submembranous cortical cytoskeleton at cell- cell adhesion sites. Furthermore, we show that its localization into t his structure is triggered by E-cadherin. Although SAP97 can be found in an E-cadherin/catenin adhesion complex, this interaction seems to b e mediated by the attachment of SAP97 to the cortical cytoskeleton. Ou r results are consistent with a model in which SAP97 is recruited to s ites of cell-cell contact via an E-cadherin induced assembly of the co rtical cytoskeleton.