May be involved in transcriptional regulation as a repressor of ESR1/ER-alpha signaling. Plays a role during development and organogenesis as well as in the function of the adult central nervous system (By similarity). Monosumoylated at Lys-567 by CBX4 and UHRF2. Sumoylation may potentiate ZNF131 inhibition of estrogen signaling. Sumoylation does not interfere with ubiquitination (By similarity). Ubiquitinated. Belongs to the krueppel C2H2-type zinc-finger protein family.