Calcium-dependent cell-cell adhesion molecules (cadherins): subclass specificities and possible involvement of actin bundles.

Cadherins are a family of cell-cell adhesion molecules and are divided into subclasses with distinct adhesive specificities and tissue distribution. Here we examined the distribution of cadherins at contact sites between cells expressing the same or different cadherin subclasses. Each cadherin was concentrated at the boundary between cells expressing an identical cadherin subclass, irrespective of the cell types connected. However, such localization decreased or disappeared at the boundary between cells containing different cadherin subclasses. We also found that the localization of cadherins precisely coincided with that of actin bundles; both were detected at the apical region of cell sheets. This co-localization was retained even after cells were either treated with cytochalasin D or extracted with the detergent NP40. These results suggest that each cadherin subclass preferentially interacts with its own molecular type at intercellular boundaries, and that cadherin molecules may be associated with actin-based cytoskeletal elements.