Figure 1.

Selective disruption of mGlu5-Homer reduces PSD association, but not dendritic or surface expression of mGlu5. A, Representative Western blots from coimmunoprecipitations using a pan long-Homer antibody of cortical homogenates of WT and mGlu5^R/R littermates. B, Quantified group data of the levels of mGlu5, mGlu1α, PIKE-L, and Shank3 that coimmunoprecipitate with Homer from mGlu5^R/R cortical homogenates. Values are expressed as percentage (mean ± SEM) of WT littermates (n = 3–5 mice/genotype; one-sample t test with Bonferroni correction for multiple comparisons). C, D, Representative Western blots and quantified group data demonstrating that total levels of mGlu5, mGlu1α, Shank3, FMRP, and long-Homers are normal in cortical homogenates of mGlu5^R/R mice. Values are normalized to β3-tubulin (n = 4–6 mice/genotype). E, F, Representative Western blots and quantified group data of mGlu5 levels in total, synaptoneurosome (SN) and PSD fractions of mGlu5^F/R (Het) or mGlu5^R/R littermate forebrains. Data are expressed as a percentage of WT levels. mGlu5 levels are normal in total and SN fractions but reduced in the PSD fractions of mGlu5^R/R (n = 3 mice/genotype; two-way ANOVA, Sidak's post hoc). G, Representative immunofluorescence images of mGlu5 and β3-tubulin in dendrites of dissociated cortical neuron cultures from WT, Het, or mGlu5^R/R mice. Quantified group data reveal no effect of the F>R mutation on dendritic mGlu5 levels (n = 45 dendrites [15–30 cells]/genotype from 2 independent cultures). H, Representative blots and quantified group data of total and surface (biotinylated) mGlu5 and β3 tubulin in acute hippocampal slices prepared from WT, Het, or mGlu5^R/R mice (n = 4 mice/genotype). *p < 0.05. **p < 0.01.