Transcription factor; part of the gene cluster that mediates the biosynthesis of the fungal neurotoxin cyclopiazonic acid (CPA), a nanomolar inhibitor of Ca(2+)-ATPase with a unique pentacyclic indole tetramic acid scaffold. Has no significant effect on the synthesis of 2-oxocyclopiazonic acid, cyclopiazonic acid (CPA) and their biosynthetic intermediates.