Data to accompany the manuscript "Tau Aggregation is Altered by Variations in its Projection Domain"

This study compares three N-terminal isoforms of mutant R5L and of wild type tau to investigate how this mutation and the length of the projection domain affects aggregation behavior. Tau polymers <i>in vitro</i> were examined using atomic force microscopy imaging to compare tau filament lengths and morphologies. In a complementary analysis, the total amount of polymerization was analyzed using a Thioflavin S assay. The R5L mutation has a greater impact on filament length in shorter N-terminal isoforms of tau, whereas in longer N-terminal isoforms the mutation impacts the total amount of tau aggregation. These observations suggest that the R5L mutation affects the kinetic nucleation-elongation pathway of tau fibrillization, where the mutant impacts polymer nucleation in 2N and 1N isoforms, but has a more significant impact on elongation in the 0N isoform.