MBC Videos

This article contains the following supporting material:

• video 1 (1.79 MB) - A movie showing phase-contrast, color overlay, YFP and CFP images of an RAW 264.7 macrophage transfected with YFP-PBD and CFP-actin during phagocytosis of two opsonized erythrocytes. CFP-actin localized to the leading edge of the extending pseudopodia to form a localized band of CFP-actin that moved over the erythrocyte. This band was closely followed by YFP-PBD during the closure of the phagosome. The interface formed by YFP-PBD and CFP-actin defined a region of constriction, evident as a deformation of the opsonized erythrocyte. Frames were acquired 30 seconds apart.
  
  
• video 2 (1.76 MB) - FRET stoichiometry showing phagocytosis of an opsonized erythrocyte by a macrophage expressing YFP-Cdc42 and CFP-PBD. A large EA signal was detected as soon as the erythrocyte contacted the macrophage. This region of high Cdc42 activation was restricted to the advancing tips of the pseudopod and diminished during the closure phase. A second erythrocyte bound to the surface of the macrophage in the bottom of the image indicates the rapidity of Cdc42 activation in response to FcγR ligation.
  
  
• video 3 (2.46 MB) - YFP-Rac1 and CFP-PBD interacted near the phagosome shortly after particle binding and during extension of the pseudopod. The fraction of YFP-Rac1 increased transiently during closure of the phagosome, as seen in the EA panel.
  
  
• video 4 - Uptake of an opsonized erythrocyte by a macrophage expressing YFP-Rac2 and CFP-PBD. YFP-Rac2 interacted very little with CFP-PBD during pseudopod extension, but this interaction increased transiently during closure of the phagosome, as indicated by the red flash in the EA image.
  

Prepared by: Journals Production Manager