Fig. 3. TMD length affects ER export. GMA₇ constructs containing different TMDs were expressed in COS cells and transport was probed by pulse-chase/endo H (Fig. 1): T53, wild-type TMD of ERGIC-53; T53L₂ and T53L₃, T53 elongated by two or three leucines, respectively; T4, TMD of CD4; L₁₈-L₂₆, TMDs consisting of leucine stretches of indicated length. Results are mean±s.e.m. of at least three independent experiments. * statistical significance to all bars except L₂₂ and T53L₂; ** statistical significance to T53 (P<0.05, Student's t-test).