Transcription factor involved in the regulation of fermentation and aerobic oxidation. Acts as a repressor of CYC1, which is involved in electron flow through the mitochondria under aerobic condition. Required for pseudohyphal formation upon nitrogen starvation. May be involved in viability at stationary phase and aging. Repressed by glucose and increased expression upon nitrogen depletion. Phosphorylated by CDC28. Belongs to the CSR2 family.