Transcription factor that mediates regulation of both acid- and alkaline-expressed genes in response to ambient pH. At alkaline ambient pH, activates transcription of alkaline-expressed genes (including pacc-1 itself) and represses transcription of acid-expressed genes (By similarity). Binds to DNA. Interacts with palA/prr-1, which binds to the two YPX[LI] motifs and is required for proteolytic processing (By similarity). Activated by C-terminal proteolytic cleavage by signaling protease (probably palB/RIM13) at neutral to alkaline ambient pH. Belongs to the pacC/RIM101 family.