Fig. 3: C-terminal truncation is a general phenomenon in aSyn seeding and inclusion formation in cells.

WB analyses of the truncation pattern of aSyn in primary neurons (a, b), in vivo after injection of human PFF in the striatum of WT and aSyn KO mice (c), in iPSC-derived neurons from a healthy control individual transduced with human PFF (d). Hippocampal (HIPP) and cortical (CTX) primary neurons from mice or (a) hippocampal (HIPP), cortical (CTX), or striatal (STR) primary neurons from rats (b) were treated for 10 days with 70 nM of mouse PFF. iPSC-derived neurons were treated with 70 nM of human PFF for 1, 3, 7, 10, and 14 days (d). Control neurons were treated with Tris buffer (−). The striatum of WT or aSyn KO mice was dissected after 1 h or 1, 3, or 7 days after injection with human PFF^WT (c). Cell lysates were analyzed by immunoblotting after sequential extractions of the soluble and insoluble fractions. The levels of total aSyn (SYN-1, 4B12, or 134–138 antibodies) (15 kDa, indicated by a double red asterisk; 12 kDa indicated by a single red asterisk or HMW) were estimated by measuring the WB band intensity and normalized to the relative protein levels of actin (Supplementary Fig. 9). Purple arrows indicate the intermediate aSyn-truncated fragments. All the original uncropped and unprocessed WB scans are available in Supplementary Fig. 17.