Involved in DNA damage response (DDR) mediated through its interaction with phosphorylated H2A proteins hta1 and hta2 which mark the discrete foci of DNA damage. Homodimer (PubMed:26160178). Interacts (via BRCT domain) with hta1 peptide containing the S/T-Q motif in vitro; this interaction requires phosphorylation of the hta1 peptide at the S/T-Q motif (PubMed:24806815, PubMed:26160178). Associated with chromatin. Relocalizes to discrete nuclear foci at DNA double strand breaks (DSBs) following DNA damage by the HO endonuclease and ionizing radiation (IR). Focus formation requires interaction with phosphorylated hta1 and hta2. During mitosis, localizes to spindles and concentrates at spindle midzones at late mitosis. Localization to spindle midzones requires ase1, but does not require phosphorylated hta1 nor hta2 (PubMed:24806815). Localizes to spindle midzones in anaphase (PubMed:26160178). The N-terminus adopts a forkhead-associated (FHA) like fold. BRCT domain is characteristic of proteins involved in DNA damage signaling (By similarity). It is required for localization to chromatin which flanks sites of DNA damage marked by phosphorylation of hta1 and hta2. Strongly resistant to the microtubule depolymerizing drug thiabendazole (TBZ). No effect on DNA damage sensitivity in response to ionizing radiation (IR), ultraviolet (UV), hydroxyurea (HU) or camptothecin (CPT) compared to wild-type.