POC5, the Proteome Of Centriole 5 protein-encoding gene, is a centriolar protein crucial for cell cycle progression, centriole elongation, and basal body maturation [1,2]. It binds centrins through Sfi1p-like repeats and is part of the luminal scaffold that stabilizes centrioles, playing a significant role in cilia-related biological processes [2,4].

POC5 has been strongly associated with adolescent idiopathic scoliosis (AIS). Mutations in POC5, such as p.(A429V), p.(A446T), and p.(A455P), are more prevalent in AIS patients compared to the general population [3]. The AIS-related POC5A429V mutation impairs cell-cycle progression, induces ciliary retraction, and disrupts centrosome protein interactions [5]. In zebrafish models, expression of human IS-associated POC5 variant mRNAs leads to spine deformity [6]. Also, in Tetrahymena, complete genomic knockout of TtPOC5 results in increased basal body production but reduced ciliary density [2].

In conclusion, POC5 is essential for normal centriole and cilia function. Its study, especially through gene-knockout models in zebrafish and Tetrahymena, has revealed its significance in AIS pathogenesis. Understanding POC5's role provides insights into the molecular mechanisms underlying AIS and potentially other cilia-related disorders.