Transcriptional regulator that binds to the promoter and activates the transcription of genes promoting brown adipose tissue (BAT) differentiation. Among brown adipose tissue-specific genes, binds the proximal region of the promoter of the UCP1 gene to activate its transcription and thereby regulate thermogenesis (By similarity). May also play a role in the cellular response to replication stress (PubMed:23446422). Interacts with PRDM16; the interaction is direct and may play a role in the transcription of brown adipose tissue-specific genes (PubMed:25578880). Interacts with PWWP2B (By similarity). Interacts with HDAC1; this interaction is enhanced in the presence of PWWP2B (By similarity). Belongs to the krueppel C2H2-type zinc-finger protein family. Extended N-terminus.