Figure 10.

FRAP analysis of FP-22 and VSVG at exit sites during a 10°C block. (a and b) Bleaching of single ERES in cells doubly microinjected with Sec23-EYFP and VSVG-cerulean (a) or Cerulean-22 (b). 1.5 × 1.5-μm areas (indicated by the squares in the second column) encompassing single ERES (recognized by the presence of Sec23-EYFP; a and b, middle), were bleached for cerulean with the 456-nm line of the argon laser, and recovery into the ERES of the cerulean-tagged constructs was imaged at the indicated times. Each column shows the same field visualized for the indicated protein as well as the merged image with the indicated pseudocolors. The arrows indicate the ERES that was bleached and followed during recovery. Bar, 2 μm. (c) recovery curves for VSVG (blue) or FP-22 (red) containing ERES. (d) Comparison of recovery curves for FP-22 in the ER and in ERES after bleaching of a 2.4-μm strip (see Materials and methods). FP-22 recovers with a similar rate in ERES (red) and in the entire strip (gray). In c and d, values in the ordinate are FI normalized to the prebleach value (see Materials and methods). Shown are means of acquired data ± SEM (n = 10).