Figure 8.
Segregation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) and N-methyl-d-aspartate receptor (NMDAR) in protein condensate by active Ca2+/calmodulin (CaM)-dependent protein kinase II (CaMKII). The assay includes 10 μM PSD-95, 2.5 μM GluN2Bc, 7.5 μM STGc, 10 μM CaMKII, and 10 μM CaM in the presence of Mg2+-ATP. A: magnification and Z projection of single condensates by differential interference contrast microscopy (DIC). Scale bar, 1 μm. B: line scanning of A in each color channel. C: observation of a condensate fusion event. Scale bar, 1 μm. When stimulated with Ca2+, PSD-95/STGc formed phase-in-phase while GluN2Bc/CaMKII formed a surrounding phase. This persisted even after addition of EGTA. Modified from Ref. 323, with permission from Nature Neuroscience.