Fig. 1. Kaiso NLS identification using deletion mutagenesis. (A) Schematic representation of the Kaiso deletion mutants used in the initial experiment for NLS identification. Each Kaiso deletion mutant was simultaneously fused N-terminally to ß-gal and C-terminally to GFP. (B) The positive control, a ß-gal/SV40-NLS/GFP fusion protein, localized strongly to nuclei, whereas the negative control ß-gal/GFP fusion protein localized to the cytosol following transient transfection of HeLa cells. (C) Full-length Kaiso fused to ß-gal/GFP localized to discrete nuclear dots. (D) Out of five initial Kaiso deletion mutants used for NLS analysis, only the Kaiso-4 deletion mutant, which encompassed Kaiso's zinc-finger domain, localized to the nucleus. This indicates the presence of an NLS within Kaiso amino acids 432-581. The images shown are representative of at least 100 cells observed for each construct in three independent trials. Bars, 20 µm.