Fig. 1. Stress induces cytoplasmic hSlu7 accumulation. (A) HeLa cells were mock treated (i), incubated at 42°C for 1 hour (ii) or irradiated with UV-C (0.3 J cm^–2 or 0.9 J cm^–2 as indicated on the left; iii-v). Following a 3 hour recovery period under optimal conditions, cells were fixed and hSlu7 cellular localization was observed by indirect immunofluorescence using anti-hSlu7 antibody. (left) Nuclear DNA DAPI staining; (center) anti-hSlu7 staining; (right) merged image of the two. (B) As described in A except that the cells were fixed and snRNP cellular localization was observed by indirect immunofluorescence using anti-Sm antibody. Treatments are indicated on the left. (C) As described in A except that the cells were incubated in the presence of actinomycin-D (ActD; 5 µg ml^–1) or puromycin (Puro; 300 ng ml^–1) for 3 hours before UV-C irradiation (UV-C). (D, left) Time-dependent export of hSlu7 out of the nucleus following irradiation at 0.3 J cm^–2. The y-axis indicates the proportion of hSlu7 exported out of the nucleus. (D, right) The effects of various stress conditions on the export of hSlu7 out of the nucleus. HeLa cells were subjected to various stress conditions [UV-C (0.3 J cm^–2), heat (42°C for 1 hour), H₂O₂, sorbitol (OSM), cisplatin (cisP) and Neocarzinostatin (NCS)]. 3 hours later, the cellular localization of hSlu7 was observed by indirect immunofluorescence using anti-hSlu7. The error bars represent s.d.