The invention refers to a nucleic acid construct comprising at least one activator sequence, at least one chimeric promoter module comprising a nucleotide sequence which binds a protein of the E2F family and a protein of the CDF-1 family, and at least one gene, wherein said chimeric promoter module promotes expression of the gene in the cell cycle later than the B-myb promoter but earlier than the cdc25C promoter. The invention also concerns the purification and identification of CDF-1 protein, and use of this protein to develop new control systems.