(A–C) Dynamic behavior of mCherry-SNX6 and mEmerald-Homer1c in distal dendrite. The last frame of motile SNX6-, Homer1c-positive puncta (arrowhead) in dendrite (A) with the respective kymograph of boxed area (B) is shown. A retrospective staining of MAP2 after live imaging (C) illuminates dendrite identity. (D) Superresolution images of DIV18 neurons immunostained with antibodies to SNX6, Homer1b/c, and p150Glued or DIC. Shown are representative images of dendrites outlined with dashed lines. White arrowheads indicate overlapped signals. (E) DIV14 neurons were transfected with construct expressing EGFP, treated with DMSO or Ciliobrevin D on DIV16 for 2 hr and immunostained with antibodies to Homer1b/c. (F) Quantification of puncta number per 100 μm dendrite length and mean intensity in spines for Homer1b/c in (E) (mean ± SEM, n = 30, N = 3). (G) Same as (E), shown are representative confocal images of EGFP-expressing neurons. Dashed lines outline the cell bodies. (H) Quantification of Homer1b/c distribution in the cell body and dendrites in (G) (mean ± SEM, n = 30, N = 3). (I) DIV14 neurons were transfected with construct overexpressing EGFP or p150Glued-N-EGFP, fixed on DIV16 and immunostained with antibodies to Homer1b/c. Dashed lines outline the cell bodies. (J) Quantification of Homer1b/c distribution in the cell body and dendrites in (I) (mean ± SEM, n = 30, N = 3). (K) Membrane fractions from mouse brain lysates were subjected to immunoisolation with antibodies to p150Glued or DIC coupled to Dynabeads Protein G, respectively. Shown are immunoblots probed with antibodies to SNX6, p150Glued, DIC, and Homer1b/c. (L) Hippocampal neurons cultured from Snx6fl/fl and Nestin-Cre; Snx6fl/fl mice were transfected with pLL3.7.1 on DIV14, fixed on DIV17 and immunostained with antibodies to Homer1b/c and p150Glued, DIC or EEA1. Shown are representative confocal images of dendritic segments. (M) Quantification of colocalization in (L) from 45 dendritic segments of 15 neurons (mean ± SEM, N = 2. Total length of dendrites: Snx6fl/fl/Nestin-Cre; Snx6fl/fl: 1247 μm/1058 μm for p150Glued; 1264 μm/1301 μm for DIC; 1244 μm/1291 μm for EEA1). Bars, 2 μm in (A), (D), (E) and (L), 20 μm in (G) and (I).