Figure 1.

LMB inhibits nuclear export of Stat1. 293T cells transiently expressing Stat1α-GFP fusion proteins are shown before (a, b, i, j) and after the addition of IFNγ. Cells were stimulated with IFNγ for 30 min and fixed at the indicated time points (10 min, 3 h, and 5 h) after withdrawal of the cytokine. The subcellular localization of Stat1 in the absence (a–h) and presence (i–p) of 10 ng/ml LMB was determined by fluorescence microscopy. LMB does not influence nuclear accumulation of the fusion protein (c, k) but reduces the rate of cytoplasmic translocation (compare e and g to m and o).