Fig. 4.

Influence of tau domain structure and co-factors on LLPS. a Domain organization of hTau40, K25, and K18. N1 and N2 are the two inserts not present in K25, P1, and P2 the two proline-rich regions, and R1–R4 the four pseudo-repeats. The pI and the number of lysine (K) and arginine (R) residues in hTau40, K25 and K18 are indicated. b DIC and fluorescence micrographs of hTau40, K25, and K18 solutions in the presence of different co-factors/buffer conditions. The concentration of the proteins was 50 μM. c Droplet size distribution of K18 (top) and hTau40 (bottom) after five and 20 min alongside corresponding fluorescence images. K18 (50 μM) with 125 µg ml⁻¹ polyU RNA in 25 mM HEPES, pH 7.4, was used. For hTau40 (50 μM), the same buffer was used with 10% dextran (and no RNA). Scale bar, 10 μm