May function as a general inhibitor of the histone deacetylase HDAC1. Binding to the pocket region of RB1 may displace HDAC1 from RB1/E2F complexes, leading to activation of E2F target genes and cell cycle progression. Conversely, displacement of HDAC1 from SP1 bound to the CDKN1A promoter leads to increased expression of this CDK inhibitor and blocks cell cycle progression (By similarity). Binds PAWR, POLR2J, RB1/RB, RBL1/P107, RBL2/P130, and SP1. May also bind MAPT (By similarity). Expressed in adrenal gland, brain (Purkinje cells), heart, kidney, liver, lung, muscle, ovary and testis (at the protein level). Expressed uniformly throughout the embryo until 10.5 dpc. From 11.5 dpc, the relative expression level increases in the liver, hind brain, spinal cord, dorsal root ganglia, and the posterior commissure. Belongs to the AATF family.