Zinc is specific among divalent transition metal ions in its ability to promote LLPS of tau441.
A, turbidity (OD at 600 nm) of tau441 (10 μm) in the presence of different transition metal salts (40 μm each) in a buffer containing 100 mm NaCl and 10% PEG 3. Error bars, S.D. (n = 5). B, representative fluorescence microscopy images of tau441 (10 μm) in the presence of different metal salts (40 μm each). The images were obtained at 37 °C in a buffer containing 100 mm NaCl and 10% PEG 3. Scale bars, 5 μm. C, turbidity (OD at 400 nm) of tau441 (10 μm) in low (10 mm NaCl) and high (100 mm NaCl, 10% PEG 3) ionic strength buffers containing 40 μm Zn2+ in the absence (orange) and presence (green) of 2 mm EDTA. Error bars, S.D. (n = 5). D, representative fluorescence microscopy images of tau441 (10 μm) in low (10 mm NaCl) and high (100 mm NaCl, 10% PEG 3) ionic strength buffers containing 40 μm Zn2+ in the absence (orange) and presence (green) of 2 mm EDTA. Scale bar, 5 μm.