JCS01711 Supplementary Material

Files in this Data Supplement:

• Supplemental Figure 1 -

  Fig. S1. Polymerized actin is required for the maintenance of Dyn3baa-induced filopodia. Neurons expressing Dyn3baa-GFP at 18DIV after 16 hours of exposure to either vehicle (DMSO) (A) or 1 mM LatA (B). Cells treated with LatA lost all fine dendritic protrusion structure, with Dyn3baa-GFP collecting in punctuate spots throughout the soma and dendrites. Scale bar, 5 mm.

• Supplemental Figure 2 -

  Fig. S2. Active presynaptic sites do not cluster at the tips of Dyn3baa-GFP-induced dendritic protrusions. (A) Neuron expressing Dyn3aaa-GFP at 18DIV following depolarization with high potassium ACSF containing 15 mM FM4-64. Many active synapses (red) are juxtaposed to dendritic spines. (B) Neuron expressing Dyn3baa-GFP at 18DIV following depolarization with high potassium ACSF containing 15 mM FM4-64. Few active synapses are opposed to dendritic protrusions, with most being located along the shaft of the dendrites. Scale bar, 5 mm.

• Supplemental Figure 3 -

  Fig. S3. Cortactin localizes to dendritic spines and filopodia in mature neurons. (A,A¢) Neurons at 18DIV stained with antibodies against cortactin exhibit substantial labeling of dendritic spines (high magnification in A¢). (B-B¢¢) Dyn3aaa-GFP and endogenous cortactin overlap in dendritic spines. Neurons at 18DIV expressing Dyn3aaa-GFP (B) were immunostained with antibodies to cortactin (B¢). An overlay of the two channels (B¢¢) demonstrates the colocalization between these two proteins. (C-C¢¢) Cortactin-RFP localizes to dendritic filopodia. Neurons co-expressing Dyn3baa-GFP (C) and cortactin-RFP (C¢) were fixed and imaged at 18DIV. The overlay (C¢¢) shows that exogenous cortactin trafficked mainly to the tips and base of Dyn3baa-GFP-induced filopodia, demonstrating that cortactin localizes to dendritic protrusions. Scale bar=5 mm.