FIGURE 3.

ISTIDs of human NMNAT1 and NMNAT2 mediate subcellular localization. The intracellular distribution of NMNAT ISTID deletion mutants of NMNAT1 (A), NMNAT2 (B), and NMNAT3 (C) was compared with that of the corresponding wild-type proteins (wt). The proteins were overexpressed in HeLa S3 cells, and their subcellular distribution was revealed by FLAG immunocytochemistry. For A (lower panels), Gly¹²⁴–Trp¹²⁹ (GRKRKW) within ISTID1 of NMNAT1 were mutated to alanine residues. Cell nuclei were visualized by 4′,6-diamidino-2-phenylindole (DAPI) staining (shown in blue). Scale bars = 10 μm. mutNLS, mutant nuclear localization signal.