Figure 6.
Targeting of CD7–Rho39 directly from the TGN to the apical surface. Targeting of CD7–Rho39 and CD7 was analyzed by the membrane targeting assay described in Fig. 5. In this experiment, the CD7–Rho39 fusion protein was precipitated by antirhodopsin COOH terminus mAb 1D4, and CD7 was precipitated by anti-CD7 mAb T3-3A1. (A and C) Autoradiograms of biotinylated, radiolabeled immunoprecipitates, which were analyzed by 12% SDS-PAGE. (B and D) Before the second streptavidin-agarose precipitation, fractions of total radiolabeled 1D4 or T3-3A1 immunoprecipitates were analyzed on SDS-PAGE to demonstrate that equal amounts of radiolabeled proteins were immunoprecipitated from each sample. Ap, apically biotinylated; Bl, basolaterally biotinylated.