Figure 5

Dominant-negative SNARE domains disrupt β ₁ integrin trafficking into the recycling endosome. CHO-K1 cells were transiently transfected for 22 h with GFP [A-D] or GFP-tagged constructs of truncated VAMP3 (V3cyto) [E-H], syntaxin13 (Syn13cyto) [I-L], SNAP23 (SNAP23^CΔ9 - 15 h transfection) [M-P, A'-D'], GS15 (GS15cyto) [Q-T], or VAMP4 (V4cyto) [U-X]. Cells were labeled with anti-β1 integrin antibody in serum free medium for 1 h to allow internalization of integrin-antibody complexes. Cells were then washed in 0.2 M glycine, pH 2.5, fixed, and stained for Rab11 [C, G, K, O, S, W and C'] and the intracellular integrin-antibody complexes [B, F, J, N, R, and V], or Rab4 [B']. Overlays of the Rab11 and β1 integrin staining are shown in D, H, L, P, T and X, and Rab4 and Rab11 overlays are shown in D'. Arrows indicate conventional colocalization of β1 integrin in a central Rab11-containing compartment. Images are 3 D reconstructions of a z-series. Scale bar represents 10 μm.