Figure 5

Patching of GFP-Nlg1 induced clustering of PSD-95. (A) Patching of GFP-Nlg1 with anti-GFP (green) increased the number of PSD-95 clusters in the dendrites of transfected cortical neurons (red). 'True' synapses are defined as colocalized VGlut1 (blue) and PSD-95 (red) protein clusters. Scale bar, 20 μm. (B) The density of non-synaptic PSD-95 clusters colocalized with Nlg1 is increased by patching recombinant GFP-Nlg1 at 60 minutes. (C) When synaptic clusters are excluded from analysis (by eliminating clusters that are positive for VGlut1), it is clear that the increase in PSD-95 clusters when patched with anti-GFP antibody was due to accumulation at non-synaptic sites. This clustering of PSD-95 was blocked when the carboxy-terminal region is deleted in either ΔC4 or ΔC55 mutants (*P < 0.02). Error bars are standard error.