Plays a role in DNA repair. May be a component of an E3 ubiquitin-protein ligase which promotes histone ubiquitination in response to UV irradiation. Histone ubiquitination may be important for subsequent DNA repair (By similarity). Promotes the degradation of the replication licensing factor cdt-1 during S-phase, thereby preventing rereplication of DNA during a single round of cell division. Protein modification; protein ubiquitination. Interacts with cdt-1 and cul-4. Expressed at high levels in the spermatheca of adult hermaphrodites. Expressed in proliferating larval blast cells including seam cells in the lateral hypodermis, P cells in the ventral hypodermis, and intestinal cells. Within the P cell lineage expression levels correlate with the proliferative state, being low in newly hatched larvae and then increasing in L1 as P cells begin to proliferate. Not expressed in the adult cells of the P lineage which are postmitotic. Also expressed in some non-proliferating cells such as the lateral hyp7 hypodermal cells, rectal gland and epithelial cells, and a subset of neuronal cells in the head and tail regions. Belongs to the DDB1 family.