Protocadherin alpha-9 (PCDHA9)

Protocadherin alpha-9 (PCDHA9) is a neural cadherin-like cell adhesion protein encoded by the PCDHA9 gene, which belongs to the protocadherin alpha gene cluster located on chromosome 5[1][2][3]. As a member of the cadherin superfamily and the largest group of clustered protocadherins, PCDHA9 is structurally characterized by six extracellular cadherin domains, a transmembrane domain, and a shared cytoplasmic domain encoded by constant exons[1][3][5]. These proteins mediate neural self-recognition and self-avoidance through isoform-specific homophilic interactions, assembling into cis-dimeric units on the cell surface and engaging in trans interactions to influence the establishment, maintenance, and specificity of cell-cell connections in the brain[4][5][6]. PCDHA9 is predominantly expressed in the central nervous system, with functions in neuronal circuit formation, survival, and maintenance of neuromuscular junctions[5]. Recent genetic and functional studies have implicated PCDHA9 mutations in developmental disorders such as Hirschsprung’s disease and neurodegenerative conditions including amyotrophic lateral sclerosis (ALS), where pathogenic variants impair neuronal connectivity and survival[1][5]. Despite disease associations, PCDHA9 is not currently considered a therapeutic drug target; therealtungs-action: there are no known drugs or targeted mechanisms of action for this molecule in current clinical use[3].

Other names

PCDH-ALPHA9KIAA0345KIAA0345-like 5protocadherin alpha 9PCDHA9PCDH-alpha-9