Cadherins are a group of integral membrane proteins that mediate calcium-dependent cell-cell adhesion.  By PCR of rat, mouse, and human neural cell cDNA with degenerate primers based on conserved regions of the cadherin extracellular domain, Sano et al. (1993) isolated partial cDNAs encoding pc42 and pc43 (PCDH2). They used the partial cDNAs to screen a human brain library and recovered cDNAs corresponding to the entire coding sequence of both genes.

Like typical cadherins, both pc42 and pc43 contain an N-terminal extracellular domain, a transmembrane domain, and a C-terminal cytoplasmic region. The extracellular domains of pc42 and pc43 contain 7 and 6 repeats, respectively, of a subdomain that is very similar to those of cadherins, but with characteristic properties.