Predicted to enable RNA polymerase II transcription regulatory region sequence-specific DNA binding activity and promoter-specific chromatin binding activity. Acts upstream of or within negative regulation of transcription by RNA polymerase II. Located in nucleus. Part of transcription regulator complex. Is expressed in several structures, including genitourinary system; hemolymphoid system gland; limb; liver; and retina. Orthologous to human RBL1 (RB transcriptional corepressor like 1). [provided by Alliance of Genome Resources, Apr 2022]