Fig. 1. Identification of an NLS in the p120^ctn Armadillo domain. (A) A cross-species comparison of the p120^ctn amino acid sequence revealed the presence of a highly conserved putative NLS. Key positively charged residues are boxed. p120^ctn-NLSmut denotes the point mutations generated for NLS functionality experiments in D and E. (B,C) Direct fusion of the putative p120^ctn NLS (a.a. 622-629, KKGKGKKP) to ß-galactosidase and GFP directs the heterologous fusion protein to the nuclei of HeLa and NIH 3T3 cells, respectively (ß-gal-NLS-GFP). (D,E) The functionality of the putative NLS was validated by the failure of a ß-gal-NLSmut fusion protein to localize to the nuclei of HeLa and NIH 3T3 cells, respectively. This mutant possessed a double point mutation within the p120^ctn NLS as indicated. The images shown are representative of at least 100 cells scored for each construct. Bars, 20 µm.