Protocadherin Gamma A9 (PCDHgA9)

Cadherins are calcium-dependent cell-cell adhesion molecules, and protocadherins constitute a subfamily of nonclassic cadherins. PCDHGA9 is 1 of 22 tandemly arranged genes within the PCDHG gene cluster on chromosome 5q31. The 22 PCDHG genes function as 'variable' exons that are individually spliced to a downstream constant region to form distinct PCDHG transcripts. The variable PCDHG exons encode the extracellular and transmembrane domains of the protocadherin protein, and the common region encodes the intracellular domain. By genomic sequence analysis, Wu et al. (2001) mapped the PCDHGA9 gene to chromosome 5q31, between the PCDHGB5 gene and the PCDHGB6 gene. They localized the mouse PCDHG genes to chromosome 18c.