MOLECULAR-BIOLOGY OF CADHERINS IN THE NERVOUS-SYSTEM

Cadherins are cell-cell adhesion molecules belonging to the Ca2+-depen dent cadherin superfamily. In the last few years the number of cadheri ns identified in the nervous system has increased considerably. Cadher ins are integral membrane glycoproteins. They are structurally closely related and interspecies homologies are high. The function is mediate d through a hemophilic binding mechanism, and intracellular proteins, directly or indirectly connected to the cadherins and the cytoskeleton , are necessary for cadherin activity. Cadherins have been implicated in segregation and aggregation of tissues at early developmental stage s and in growth and guidance of axons during nervous system developmen t. These functions are modified by changes in type(s) and amount of ca dherins expressed at different developmental stages. The regulatory el ements guiding cadherin expression are currently being elucidated.