Transcription coregulator involved in regulation of gene cluster that mediates the biosynthesis of aspergillic acid, a hydroxamic acid-containing pyrazinone with aliphatic side chains that originates from leucine (Leu) and isoleucine (Ile) (PubMed:29674152). Aspergillic acid has antibiotic properties and was shown to be lethal to mice (PubMed:29674152). Secondary metabolite biosynthesis. Expressed during the earliest stages of maize kernel infection (PubMed:23834374). Leads to the down-regulation of expression of asaB, asaC, asaD, and asaR; and completely abolishes ferriaspergillin production (PubMed:29674152).