Figure 2
APP is rapidly trafficked from the Golgi apparatus to LAMP1-labeled compartment. Photoactivation targets were drawn on the Golgi apparatus (white dots with arrows). For 15 minutes, cells were alternately imaged and irradiated (photoactivated) with 405 nm laser light within the targets. White arrowheads point to APP-paGFP colocalized with Lamp1-mRFP. Scale Bar = 5 μm. a) Demonstrates rapid transport of Full length-APP- paGFP (top panel) and βAPP-paGFP (middle panel) from Golgi apparatus to a LAMP1-labeled compartment. The same trafficking occurs in mouse primary neurons (lower panel). (See Additional file 3: Video S1). b) Higher magnification images of βAPP-paGFP trafficking rapidly to a LAMP1 labeled compartment. Scale Bar = 1 μm. c) Comparison of the colocalization of activated FL-APP-paGFP (n = 9) and activated βAPP-paGFP (n = 8). d) SN56 cells transiently transfected with the secretory protein Vesicular Stomatitis Virus Glycoprotein-paGFP (VSVG-paGFP), GalT-CFP (blue), and LAMP1-mRFP (red) to demonstrate that very little of the green photoactivated VSVG-paGFP arrives in the LAMP1 compartment; paGFP does not alter trafficking. Scale bars = 5 μm. e) Transfected SN56 cells were treated for 5 minutes with nocodazole before imaging (See Additional file 5: Video S2) Scale bars = 5 μm. f) Z-stack of the same cell taken immediately following 15 minutes of photoactivation demonstrating that green signal remains inside the Golgi.