FIGURE 7.

Ubiquitination regulates the mGluR-mediated AMPAR trafficking. A, examples of dendritic staining for surface GluA1 (red) and Bassoon (green) after R,S-DHPG treatment. B, quantitation of synaptic GluA1 clusters (synapses defined by Bassoon staining) before and after the R,S-DHPG treatment. C, representative images showing that acute knockdown of Siah-1A did not have any effect on the surface expression of GluA1 containing receptors. D, quantitation of the effect of acute knockdown of endogenous Siah-1A on the surface expression of GluA1 containing receptors. E and F, on the other hand, cells in which endogenous Siah-1A was knocked down showed enhanced mGluR-mediated AMPAR endocytosis as compared with control cells on application of 100 μm R,S-DHPG as shown in representative images (E) and quantitation (F). All the results are represented as means ± S.E., collected from three independent experiments. Scale bar, 10 μm. ***, p < 0.001; **, p < 0.01; n.s, p > 0.05.