Western blotting of LRRK2. A. Recombinant LRRK2 (arrowhead) from transfected (+) HEK 293T and M17 cells was specifically recognized by all four LRRK2 antibodies (Ab1, Ab2, Ab3, and Ab4) used in this study. LRRK2 was not recognized in non-transfected cells (-). B. Recombinant LRRK2 (arrowhead) from transfected M17 cells is detected by anti-LRRK2 Ab4 (lane 1), but not after absorption of the antibody with its peptide antigen (lane 2). Brain LRRK2 was recognized by anti-LRRK2 Ab4 in two controls (lanes 3 and 4) and two PD cases (lanes 5 and 6). Cell lysates (10 μg protein) and brain homogenates (100 μg protein) were prepared and loaded on 6% SDS-PAGE gels for Western blot analysis using anti-LRRK2 antibodies Ab1–Ab4 in (A) and Ab4 in (B).