C) Fluorescence micrographs showing that although TOG D1 and hnRNPF PLD partition into hnRNPA2 LC droplets (rows 1 and 3), they are unable to partition into tyrosine phosphorylated hnRNPA2 LC droplets (rows 2 and 4). Conditions: 20 µM proteins (~1% fluorescently labeled), 20 mM MES pH 5.5, 50 mM NaCl, 150 mM urea. Scale bar: 10 µm. D) Phosphomimic variants containing 5 or 12 serine to glutamate substitutions (hnRNPA2 LC5E and hnRNPA2 LC12E, respectively) both allow partitioning of TOG D1 and hnRNPF PLD, even though hnRNPA2 LC12E barely phase separates at these conditions, indicating that increased negative charge is insufficient to prevent partitioning of TOG D1 and hnRNPF PLD. See Appendix Figure S7B for quantification of LLPS of hnRNPA2 LC5E and hnRNPA2 LC12E. Conditions: 20 µM proteins (~1% fluorescently labeled), 20 mM MES pH 5.5, 50 mM NaCl, 150 mM urea. Scale bar: 10 µm. 