CRACR2a cortical puncta comigrate with F-actin retrograde flow at the IS. (A) GFP-CRACR2a puncta migrate with actin retrograde flow. GFP-CRACR2a-expressing Jurkat cells were allowed to settle on anti-CD3–coated glass and were either not treated or treated with 2 µM LatA for 5 min to depolymerize actin. Kymographs are derived from the yellow dashed lines indicated on the images. Scale bar: 10 µm. (B) Velocities of the CRACR2a cortical puncta and actin retrograde flow. Velocities are quantified based on at least 50 kymograph traces from eight cells in each condition. Data are mean ± SD.