Figure 5.

Cotransport of SCb proteins continue in F-actin-depleted axons. A, Cultured hippocampal neurons were double transfected with mRFP::α-SYN and GFP::SYS-I, respectively, treated with 5 μm latrunculin for 18–24 h, and visualized by simultaneous dual-color video microscopy. Selected frames from a time-lapse sequence show a single mRFP::α-SYN particle and a GFP::SYS-I particle cotransported anterogradely (arrowhead, yellow in merged). Kymographs generated from the movies in the red/green channel are shown as well. Note that the two fusion proteins colocalize precisely during transport, suggesting that the α-synuclein/synapsin-I complex is not disrupted by actin depletion. B, Axons double transfected with mRFP::α-SYN and GFP-tagged synapsin-I or GAPDH were treated with a high dose (50 μm) of latrunculin, known to cause acute disruption of F-actin, and then imaged with dual-color simultaneous video microscopy. Note that cotransport of α-synuclein and synapsin-I or α-synuclein and GAPDH continues under these conditions as well.