Required for pre-mRNA splicing as component of the spliceosome (, ). As a component of the minor spliceosome, involved in the splicing of U12-type introns in pre-mRNAs (Probable). E3 ubiquitin-protein ligase that catalyzes the transfer of ubiquitin onto target proteins (, ). Catalyzes polyubiquitination of SNRNP200/BRR2 with non-canonical 'Lys-63'-linked polyubiquitin chains . Plays a role in DNA repair via its role in the synthesis of 'Lys-63'-linked polyubiquitin chains that recruit ALKBH3 and the ASCC complex to sites of DNA damage by alkylating agents . Ubiquitinates CXCR4, leading to its degradation, and thereby contributes to the termination of CXCR4 signaling .
Subcellular locations: Nucleus, Nucleus speckle
Colocalizes with ASCC2 in nuclear foci after DNA damage by alkylating agents. In the absence of DNA damage, colocalizes with the spliceosome components SNRNP200/BRR2 and PRPF8 in nuclear speckles.
Ubiquitous.