Endosomal sorting of CD147 requires microtubules. (A) HeLa cells overexpressing HA-Hook1 were untreated (Control) or pretreated with nocodazole for 2 h at 37°C before anti-CD147 antibody internalization for 30 min. (B) Untransfected HeLa cells were treated as described in A and then fixed and labeled with antibodies to EEA1. (C) Cells were incubated with CD147 antibody and Alexa Fluor 594–conjugated transferrin for 30 min at 37°C in control or nocodazole-containing media. Then the cells were fixed and stained with the respective secondary antibodies. Insets show enlarged views of the boxed panels. Bars: (A–C) 10 µm; (A and B, insets) 5 µm; (C, insets) 3 µm.