Recent progress in protocadherin research

Protocadherins constitute a large family belonging to the cadherin superfam ily and function in different tissues of a wide variety of multicellular or ganisms. Protocadherins have unique features that are not found in classic cadherins. Expression of protocadherins is spatiotemporally regulated and t hey are localized at synapses in the CNS. Although protocadherins have Ca2-dependent hemophilic interaction activity, the activities are relatively w eak. Some protocadherins have heterophilic interaction activity and the cyt oplasmic domains associate with the unique cytoplasmic proteins, which are essential for their biological functions. Given the characteristic properti es, the large size, and the diversity of members of the protocadherin famil y, protocadherins may participate in various biological processes. In parti cular, protocadherins seem to play a central role(s) in the CNS as related to synaptic function. (C) 2000 Academic Press.