Rab27b is Involved in Lysosomal Exocytosis and Proteolipid Protein Trafficking in Oligodendrocytes

Co-localization of Rab27b with PLP and Cathepsin D in Cultured Oligodendrocytes and in Brain Slices. A Double staining for galactocerebroside (Galc+, mature oligodendrocyte marker, green) and Hoechst (nuclear marker, blue) shows that most Hoechst+ cells also expressed Galc-IR. Scale bar, 25 μm. B, C Co-immunostaining for PLP, Rab27b, and cathepsin D reveals co-localization of Rab27b with PLP in late endosomes/lysosomes of cultured oligodendrocytes (B) and in rat brain slices (C). Confocal planes are shown; lower panels are enlarged images from upper panels. Scale bars, 25 μm (upper panels) and 5 μm (lower panels). D, E Summary of the co-localization of PLP with Rab27b or cathepsin D in cells (n = 5) (D) and slices (n = 5) (E). Error bars indicate SEM