Plays a role in microtubule organization and/or maintenance for the formation of primary cilia (PC), a microtubule-based structure that protrudes from the surface of epithelial cells. Plays a critical role in G2/M checkpoint and nuclear divisions. A key player in the DNA damage-activated ATR/ATM signaling cascade since it is required for the proper phosphorylation of H2AX, RPA, CHEK2 and CHEK1. Plays a critical role in chromosome segregation, acting as a mediator required for the maintenance of genomic stability through modulation of MDC1, RPA and CHEK1. Interacts (via N-terminus) with ATRIP. Interacts with ATM, ATR and MDC1. Interacts with XPA (via N-terminus) upon UV irradiation. Interacts with CEP83, CCDC92, TTBK2, DVL3, NPHP3 and weakly with NPHP4. Interacts with DZIP1 (By similarity). Localizes specifically to very distally located appendage structures on the mature centriole from which initiate PC formation (PubMed:26337392). Persisted at centrioles throughout mitosis. Expressed in chromatin-enriched nuclear fraction of HeLa cells. In response to DNA damage, it translocates to nuclear foci that contain the DNA damage response proteins KAT5/TIP60 and CHEK1. Expressed in several cell lines. Phosphorylation at Ser-186 is induced upon DNA-damage caused by treatment with IR irradiation, UV irradiation, hydroxyurea or amphidicolin. Also MDC1-mediated chromatin remodeling is critical for DNA damage-induced phosphorylation. The disease is caused by variants affecting the gene represented in this entry. Contaminating sequence. Potential poly-A sequence. Contaminating sequence. Potential poly-A sequence.