PARK7 and Parkinson disease: To study the function of WT DJ-1 and loss of function DJ-1 mutations in mitochondrial ATP production, we expressed DNA constructs for known PD-associated DJ-1 mutations (M3 = A104T; M4 = D149A; M5 = L166P;12 and for WT DJ-1 in HEK 293T cells; we also purified the proteins).