Figure 1.

Clathrin-mediated internalization in DKOS cells. (A) DKOS cells were treated with mouse anti-chicken IgM at 4°C, incubated at 37°C for 0 and 5 min, and then fixed and permeabilized. BCR was detected with an FITC-conjugated anti-mouse IgG and clathrin with polyclonal anti-CLC rabbit serum plus Rhodamine Red-conjugate anti-rabbit IgG. Immunofluorescent images of a central cell section showing the localization of the BCR (green), clathrin (red), and nucleus (blue). Yellow arrowheads denote colocalized BCR and CHC. Scale bar, 10 μM. (B) DKOS cells were untreated (-) or treated with 10 μg/ml goat anti-chicken IgM at 37°C for 0–20 min. CHC, immunoprecipitated with the mAb X22, was resolved by electrophoresis and immunoblotted for phosphotyrosine (pTyr) and CHC.