Fig. 3. Nup214 and Nup88 are interdependent. (A) Nup88 degradation in nup214 RNAi cells is prevented by epoxomicin. Drosophila S2 cells were transfected with dsRNA against nup214. On day 3 post transfection, cells were treated with epoxomicin (or DMSO) for 0, 8 or 16 hours. Cell lysates were analyzed by western blot with Nup214 or Nup88 antibodies. ß-tubulin served as a loading control. The arrow indicates the Nup88-specific band. The graph shows the levels of Nup88 (grey) and Nup214 (black) normalized against ß-tubulin. The western blot to the right represents a control for the specificity of the Nup88 antibody. Drosophila S2 cells were exposed for 4 days to nup88 RNAi. The Nup88-specific band (arrow) is absent in the RNAi cells. (B) Nup88 anchors Nup214 at the nuclear rim. Either Nup214 or Nup88 was expressed by the hsp70 promoter in wild-type, mbo or nup214 mutant larvae. The images show confocal sections of malpighian tube nuclei stained with anti-Nup214 and anti-Nup88. Bars, 5 µm.