Protocadherin

Protocadherins (Pcdhs) are the largest mammalian subgroup of the cadherin superfamily of homophilic cell-adhesion proteins. They were discovered by Shintaro Suzuki's group, when they used PCR to find new members of the cadherin family. The PCR fragments that corresponded to Protocadherins were found in vertebrate and invertebrate species This prevalence in a wide range of species suggested that the fragments were part of an ancient cadherin and were thus termed "Protocadherins" as the "first cadherins"; although, of the approximately 70 Pcdh genes identified in mammalian genomes, over 50 are located in tightly linked gene clusters on the same chromosome, and this kind of organization can only be found in vertebrates.