Fig. 1: CypA catalyzes aSyn aggregation.

a HT-22 cells transfected with CypA and aSyn and stained for aSyn (green), CypA (red), and DNA (DAPI, blue) were imaged at 63× original magnification using a confocal microscope. Scale bars represent 10 µm. The images were acquired from n = 10 fields of 2 independent experiments. b, Western blots from HEK293T cells transfected for 72 h with aSyn, as well as empty vector or CypA plasmids expressing for 72 h following Sarkosyl-insoluble fractionation. n = 3 independent experiments were performed. c, g ThT-fibrillization assay of aSyn alone (30 μM, green) and in the presence of increasing concentrations of wild-type CypA (c) or the functionally impaired R55A/K82A mutant of CypA (g). Data points represent the mean values from n = 4 independent experiments ±1 standard deviation (SD). d Schematic representation illustrating catalysis of IDP misfolding by CypA. The aggregate was prepared with PyMol v. 1.7.6.0 using aSyn amyloid fibrils (PDB code: 6A6B). e, h Aggregation half-times of aSyn alone (yellow), and in the presence of increasing concentrations of wild-type CypA (e) or the R55A/K82A mutant of CypA (h). Data points represent the mean values from n = 4 independent experiments ±1 SD. f 3D structures of the active site of CypA. R55 and K82, which are important for CypA activity, are highlighted in red.