Ubiquitination regulates the group I mGluR internalization in HEK293 cells.
A, representative images showing inhibition of DHPG-mediated endocytosis of myc-mGluR1 on application of PYR-41 in HEK293 cells. B, quantitation of the effect of PYR-41 on the internalization of myc-mGluR1. C, co-immunoprecipitation assays demonstrate that application of PYR-41 inhibits ligand-induced ubiquitination of mGluR1. M, molecular weight markers; V, empty vector. D and E, representative images (D) and quantitation (E) of DHPG-induced myc-mGluR5 internalization suggest that application of PYR-41 also inhibits the endocytosis of myc-mGluR5. All the results are represented as means ± S.E., collected from three independent experiments. Scale bar, 10 μm. ***, p < 0.001; n.s, p > 0.05.