Required for promoter sequence element PCB-driven, M-phase-specific transcription. Acts as a transcriptional activator with a role in the regulation of mitosis. Binds, cooperatively with mcm1, the CLB cluster regulatory elements throughout the cell cycle. Regulates the periodic transcription of cdc15 and spo12. Required for the correct timing, positioning and contraction of the division septum. Phosphorylated. Occurs periodically during mitosis.