Movie 5

The actin and microtubule cytoskeletons are coordinately regulated in a Rap-dependent manner during B cell spreading. Vector control and RapGAPII-expressing A20 cells that had been transfected with F-tractin-tdTomato (red) and GFP-α-tubulin (green) were allowed to attach to anti-Ig-coated coverslips. Time-lapse spinning disk confocal microscopy was used to acquire images every 40 s between 5 min and 15 min. 3D reconstruction of z-stacks (0.5 μm step size) with side and top views of the cells are played back at 5 frames per second (120X real time).

The Rap1–cofilin-1 pathway coordinates actin reorganization and MTOC polarization at the B cell immune synapse

Jia C. Wang, Jeff Y.-J. Lee, Sonja Christian, May Dang-Lawson, Caitlin Pritchard, Spencer A. Freeman, and Michael R. Gold

J Cell Sci 2017. 130:1094-1109; doi: 10.1242/jcs.191858