A deletion of the C-terminal NLS of FANCI fails to correct MMC sensitivity in the FA-I F010191 fibroblasts. (A,C) F010191 fibroblasts were transfected with empty vector or the indicated FANCI expression constructs. Forty-eight hours after transfection, cells were treated with 2mM HU for 24 hours and FANCD2 monoubiquitination was assessed by Western blot analysis and probed with the indicated antibodies. The L/S ratio was calculated as described in Figure 3A. (B,D) FA-I F010191 fibroblasts were transfected with either empty vector or the indicated FANCI expression constructs; and 48 hours after transfection, cells were treated with MMC at the indicated dose for 5 more days. Percentage cell survival is shown as an average of 3 independent experiments. Error bars represent the SD for the different experiments performed.