Enables transcription coactivator activity and ubiquitin protein ligase activity. Involved in positive regulation of Golgi lumen acidification and regulation of circadian rhythm. Acts upstream of or within several processes, including cellular protein metabolic process; positive regulation of phosphatidylinositol 3-kinase signaling; and reproductive structure development. Located in cytosol and nucleus. Is expressed in central nervous system and retina. Used to study Angelman syndrome. Human ortholog(s) of this gene implicated in Angelman syndrome. Orthologous to human UBE3A (ubiquitin protein ligase E3A). [provided by Alliance of Genome Resources, Apr 2022]