FIGURE 3.

NLS-mediated nuclear import of IP3KB. H1299 and HeLa cells were transfected with different EGFP fusion genes. After 24 h of expression, cells were fixed, and the nuclear/cytoplasmic ratio of EGFP fluorescence was determined. Constructs used encode EGFP fusion proteins of wild type HsIP3KB (WT) and forms with a mutated NLS (mNES-1/2/3/4/5). Additionally, EGFP alone (EGFP) and EGFP fused with the isolated NLS (NLS/EGFP) were expressed. In some experiments, cells were treated with 20 nm LMB for 6 h (+LMB). If not otherwise indicated, values were always compared with HsIP3KB/EGFP. For further details, see the legend to Fig. 2. For detailed information about the constructs, see Table 1.