Subcellular localization of deletion mutants of Rpp38. ECFP-Rpp38 constructs were transiently transfected into HEp-2 cells. Cells were fixed with methanol/acetone, and the fluorescent proteins were visualized by direct fluorescence microscopy (panels 1, 3, 5, and 7). Phase-contrast images of the same cells are shown in panels 2, 4, 6, and 8. Panels 1 and 2: ECFP-Rpp38; panels 3 and 4: ECFP-Rpp38 Δ(1–98); panels 5 and 6: ECFP-Rpp38 Δ(1–141); and panels 7 and 8: ECFP-Rpp38 Δ(181–283).