Cadherins and tissue formation: integrating adhesion and signaling.

Cadherins and other cell-substrate and cell-cell adhesion molecules play an essential role during development. Through their cytoplasmic interaction with the cytoskeleton, cell adhesion molecules physically link cells with the extracellular matrix and/or with each other. These interactions create architectural and structural entities that enable the tissues in the embryo to restrain the physical forces encountered during development. Regulated cell adhesion is also often the driving force of morphogenetic movements. This review goes beyond the adhesive aspect of cadherins, focusing on their roles as signaling molecules in development. We discuss how cadherins, through their effects on cell proliferation, cell death, cell polarization, and differentiation, play a role in the formation of tissues and organs in the developing embryo.