Enables HLH domain binding activity and SUMO conjugating enzyme activity. Involved in several processes, including negative regulation of transcription by RNA polymerase II; nuclear export; and protein sumoylation. Acts upstream of or within positive regulation of canonical NF-kappaB signal transduc
tion. Located in nuclear body. Part of SUMO ligase complex. Is active in several cellular components, including Schaffer collateral - CA1 synapse; postsynaptic cytosol; and presynaptic cytosol. Is expressed in several structures, including early embryo; forebrain; forelimb bud; limb; and oocyte. Orthologous to human UBE2I (ubiquitin conjugating enzyme E2 I). [provided by Alliance of Genome Resources, Jul 2025]