Figure 6
From: Axonal BACE1 dynamics and targeting in hippocampal neurons: a role for Rab11 GTPase
Rab11b GTPase activity regulates axonal targeting of BACE1. (A) DIV12 neurons co-transfected with BBS-BACE1-YFP and mCherry-Rab11b WT or Rab11bS25N dominant-negative mutant were labeled with AF647-BTX uptake followed by an acid wash to selectively visualize internalized BACE1. Dendrites and axons were identified by MAP2 immunostaining of fixed neurons. The pseudocolor images depict total (YFP) and internalized BACE1 (BTX) fluorescence intensities in the same neuron. (B) Higher magnification of dendrite and axon segments (rectangle boxes) of neurons shown in A. (C) Higher magnification of the cell bodies (square boxes) of neurons shown in A. (D) Mean axon-to-dendrite fluorescence intensity ratios for total (YFP) and internalized BACE1 (BTX) were quantified from individual neurons cotransfected with BACE1 and empty vector, Rab11b WT or Rab11S25N (n = 14-15 neurons each). (E) Mean cell body-to-dendrite fluorescence intensity ratios for total and internalized BACE1 were quantified. Note that expression of Rab11S25N resulted in a significant decrease of axonal BACE1 localization and an increase of BACE1 levels in the cell body.