Figure 8.

nPIST regulates AMPAR clustering. Constructs encoding nPIST-GFP, nPIST(1-312)-GFP, and stargazin-HA were transfected into neurons, which were then fixed (at 11-17 d in vitro) and stained for GFP (green) or GM130, HA, or GluR1 (red). When transfected alone, nPIST-GFP (green) colocalizes with GM130 (red) in the Golgi as well as in puncta and diffusely within dendrites (A-C). When cotransfected with stargazin-HA (red), both proteins colocalize perinuclearly and in dendrites (D-F). nPIST-GFP, when transfected alone, results in a small but significant increase in AMPAR clustering (red) (G-I). In contrast, nPIST(1-312)-GFP (green) dramatically reduces the intensity of GluR1 synaptic clusters (red) (J-L). Merged images are shown in C, F, I, and L. Scale bar, 10 μm. M, Insets from H and K showing 6× digital magnification of GluR1 staining in transfected or control cells for nPIST-GFP and nPIST(1-312)-GFP.