Enables DNA-binding transcription factor binding activity and transcription corepressor activity. Acts upstream of or within several processes, including determination of adult lifespan; negative regulation of transcription by RNA polymerase II; and regulation of skeletal muscle fiber development. Part of histone methyltransferase complex. Is expressed in several structures, including 2-cell stage embryo; future midbrain; heart; nervous system; and trunk myotome. Orthologous to human HDAC9 (histone deacetylase 9). [provided by Alliance of Genome Resources, Apr 2022]