Transcription factor that regulates pH-induced filamentation with RIM101. Required for yeast cell adherence to silicone substrate and biofilm formation. Expression is down-regulated during growth at pH 8 by the pH-responsive transcription factor RIM101. Induced during exposure to the weak acid stress of acetic acid, through the regulation by the transcription factor MNL1. Decreases cell adherence to silicone substrate. Blocks biofilm formation.