C2ORF62

C2ORF62 Full Name

ciliogenesis associated TTC17 interacting protein

C2ORF62 Introduction

C2orf62, officially designated as ciliogenesis associated TTC17 interacting protein (CATIP), is a protein encoded by a gene on chromosome 2p14-p13.3 that has been implicated in the regulation of ciliogenesis and centrosome biology. Initially characterized as an uncharacterized open reading frame (C2orf62), the protein has since been functionally linked to the process of primary cilium formation through its interaction with tetratricopeptide repeat domain 17 (TTC17). Primary cilia are solitary, microtubule-based sensory organelles that protrude from the surface of most quiescent vertebrate cells and serve as signaling hubs for developmental pathways including Hedgehog, Wnt, and PDGF signaling.

Figure 1. Strcuture of C2ORF62.

Ciliogenesis and Centrosomal Functions
CATIP/C2orf62 localizes to the basal body and centrosome, the microtubule-organizing centers that serve as the foundation for primary cilium assembly. Through its interaction with TTC17 and potentially other centrosomal proteins, CATIP participates in the early stages of ciliogenesis, including the docking of preciliary vesicles to the distal end of the mother centriole (basal body) and the extension of the ciliary axoneme. Loss of CATIP function leads to impaired primary cilium formation in cultured cells, with reduced ciliation frequency and shortened cilia in cells that do form them. The protein contains predicted coiled-coil domains that likely mediate protein-protein interactions within the centrosome-cilium interface. CATIP is regulated in a cell cycle-dependent manner, with expression peaking during G0/G1 when primary cilium assembly occurs, and declining during mitosis when the cilium is resorbed.

Ciliopathies and Cancer Implications
Given its role in primary ciliogenesis, CATIP/C2orf62 is positioned at the nexus of ciliopathy biology. Ciliopathies are a spectrum of human genetic disorders caused by defects in cilia structure or function, including polycystic kidney disease, Bardet-Biedl syndrome, Joubert syndrome, and nephronophthisis. While specific CATIP mutations have not yet been causally linked to a defined ciliopathy, its functional involvement in cilium biogenesis makes it a candidate gene for ciliopathy screening panels. In cancer biology, primary cilia can function as either tumor suppressors or tumor promoters depending on the oncogenic context: loss of cilia is frequently observed in renal cell carcinoma and pancreatic cancer, while cilia are maintained in medulloblastoma and basal cell carcinoma driven by Hedgehog pathway activation. The role of CATIP in tumorigenesis may therefore be highly context-dependent. Future studies are needed to delineate the full spectrum of CATIP interactors and its contribution to cilium-dependent signaling in development and disease.

Alternate Names for C2ORF62

chromosome 2 open reading frame 62; MGC50811; hypothetical protein LOC375307; OTTHUMP00000164138