The tetracycline response element with a bidirectional CMV promoter drives inducible expression of the four-repeat domain on human MAPT (TauRD; 244-372 aa) carrying the frontotemporal dementia and parkinsonism linked to chromosome 17 Lys280 deletion (deltaK280) and two proline mutations in the hexapeptide motifs, I277P and I308P, and a luciferase gene. The Lys280 deletion accelerates aggregation while the proline mutations inhibit MAPT (Tau) aggregation.