Figure 4.

TAT-S845 peptide inhibits GluR1 phosphorylation of S845 on PKA site and surface expression of GluR1 and GluR2 in a time-dependent manner. Hippocampal neurons (10 d in vitro) were treated with peptide TAT-S845 or scrambled control (Con) peptide TAT-SCR (80 μm) for the times indicated. Data were combined from two to three independent experiments. A, After 2 h treatment, phosphorylation of GluR1 at S845 was significantly reduced (n = 18; one-way ANOVA, p < 0.001; Con vs TAT-S845, **p < 0.001; TAT-SCR vs TATS845, **p < 0.001). B, C, After 3 d of treatment, phospho-GluR1S845, phospho-GluR1S831, and phospho-synapsin I were determined (one-way ANOVA, *p = 0.0217; n = 30). D, Surface GluR1 or GluR2 was determined by biotinylation assay after TAT-S845 and TAT-SCR treatment (n = 38; GluR1, one-way ANOVA, **p = 0.0095; GluR2, one-way ANOVA, **p = 0.0053). Error bars indicate SE.