Enables RNA polymerase II transcription regulatory region sequence-specific DNA binding activity. Contributes to histone deacetylase activity. Involved in histone H3 deacetylation. Located in nucleus. Human ortholog(s) of this gene implicated in Machado-Joseph disease. Orthologous to several human genes including ATXN3 (ataxin 3). [provided by Alliance of Genome Resources, Apr 2022]