Figure 5.

The COOH-terminal cleavage fragment of p115 induces Golgi fragmentation and apoptosis. COS7 cells were transfected with FLAG-tagged full-length p115, NH₂-terminal fragment (p115_1–757), or COOH-terminal fragment (p115_758–962). Cells were fixed 20 h after transfection and stained with a TGN38 (green) antibody, a FLAG (red) antibody, and Hoechst 33238 (blue). Full-length p115 and p115_1–757 localized predominantly to the Golgi region and their expression did not affect Golgi morphology or cell viability in transfected cells. In contrast, p115_758–962 staining was diffuse in the cytoplasm and concentrated in the nucleus. Most significantly, expression of p115_758–962 induced Golgi fragmentation and apoptosis, as indicated by TGN38 and Hoechst staining, respectively. The “single cell” panels show enlarged merged images of a representative cell transfected with each construct. Arrows indicate transfected cells. Bars, 10 μm.