Figure 1.

ArcKR Mice Exhibit Defects in Ubiquitin-Mediated Turnover of Arc

(A and B) Blots showing increased Arc protein in ArcKR hippocampal cultures treated with DHPG (100 μM DHPG; 10 min) and harvested 15, 30, 60, 120, 240, 360, and 480 min after DHPG washout.

(C) Blots showing that Arc turnover is faster in WT neurons.

(D) Blots showing that Arc turnover is blunted in ArcKR neurons.

(E) Blot of K48-linked ubiquitin showing loss of Arc ubiquitination in ArcKR mice after pilocarpine induced class III seizure. Actin was used as a loading control.

(F and G) ArcKR neurons have increased GluA1 endocytosis. Odyssey CLx scans for surface and internalized AMPAR subunits in WT and ArcKR hippocampal neurons at 5 and 15 min after DHPG washout (F). Graph represents surface fluorescence normalized to the total fluorescence intensity (G).

(H and I) The same experimental condition as in (G) showing that ArcKR neurons have increased surface levels of GluA2. Statistical comparisons were carried out using one-way ANOVA, paired and unpaired Student’s t tests. ^∗p ≤ 0.05; ^∗∗p ≤ 0.005; n = 3 technical replicates from 3 independent experiments. Values represent mean ± SEM.