Transcription factor capable of interacting with purine rich repeats (GA repeats) (PubMed:8441384, PubMed:10675337, PubMed:8816484). Acts as a a master regulator of nuclear-encoded mitochondrial genes (By similarity). (Microbial infection) Necessary for the expression of the Adenovirus E4 gene. Heterotetramer of two alpha and two beta subunits (PubMed:7799916). Interacts with HCFC1, causing repression of transcriptional activity (PubMed:10675337). Acetylated by EP300/p300. Deacetylated by SIRT7, promoting heterotetramerization and activity.