Figure 3.

Recycling from endosomes is unaffected by dyn1(K44A) or dyn2(K44A). Adenovirally infected tTA-HeLa cells (A) or MDCK T23 cells (B) overexpressing dyn1(wt) (□); dyn1(K44A) (▪); dyn2(wt) (Δ), or dyn2 (K44A) (▴) were cultured for 18 h after infection in the presence (A) or absence (B) of 5 ng/ml tet. (A) HeLa cells were then loaded with B-Tfn at 37°C to steady state. Surface bound B-Tfn was masked with avidin at 4°C and the recycling of intracellular B-Tfn was determined after incubation at 37°C for the indicated times as described in Materials and Methods. (B) MDCK T23 cells were incubated with ¹²⁵I-IgA at 4°C for 60 min and unbound IgA was eliminated by three quick washes with cold media. Surface bound ligand was internalized by warming the cells to 37°C for 5 min. Cells were then cooled down, cell surface IgA was removed by trypsin treatment, and the recycling of intracellular ¹²⁵I-IgA was determined, as described in Materials and Methods, after incubation at 37°C for the indicated times. Results shown are average of three experiments.