Fig. 4.

PA-processing assay in ARAP3-deficient cells. (a) Western blot analysis of bound and internalized PA. PA binding and internalization assays were done as described in Material and Methods. Lanes: c, naïve M2182-tTA cells; 1, F7 cells; 2, pooled M2182-tTA cells expressing ARAP3 antisense EST. PA83 is the full-length form of PA (83 kDa), and PA63 is the furin-cleaved form of PA (63 kDa); the oligomer represents the homoheptamer of PA63. Tubulin Western blotting was used as a control for equal loading. (b) Confocal microscopy imaging. Binding and internalization of Alexa Fluor 488-labeled PA83 were examined as described in Materials and Methods.