Files in this Data Supplement:

• Supplemental Movie 1 (QuickTime, 294 KB) - Real time measurement of targeting of GEM domains to the immune synapse of APCs. Fluorescence (top) and DIC (bottom) images of an antigen-pulsed CH27 cell expressing L₁₀-GFP as it forms an immune synapse with a D10 T cell. Each frame was collected 1 min apart.
• Supplemental Movie 2 (QuickTime, 1490 KB) - Real time measurement of L₁₀-GFP mobility in an MβCD-treated CH27 cell. FRAP experiment of an MβCD-treated CH27 cell expressing L₁₀-GFP. Each post-bleach frame was collected 7 s apart.
• Supplemental Movie 3 (QuickTime, 1586 KB) - Real time measurement of L₁₀-GFP mobility in the immune synapse of a CH27 cell. FRAP measurement of an antigen-pulsed CH27 cell expressing L₁₀-GFP and conjugated to a D10 T cell. Each post-bleach frame was collected 7 s apart.
• Supplemental Movie 4 (QuickTime, 3470 KB) - Real time measurement of exchange of L₁₀-GFP between the immune synapse and remaining compartments of the CH27 cell. FLIP experiment of a CH27 cell expressing L₁₀-GFP and conjugated to a D10 T cell. A region of the immune synapse was repeatedly photobleached with 5 s pulses of laser illumination.