Fig. 4.

Knockdown of ELYS leads to cell division defects. HeLa cells were transfected with control, ELYS or Nup133 siRNA duplexes for 48 h. (A) ELYS RNAi in HeLa cells leads to reduced levels of both ELYS and Nup133 (red, and Insets) at the kinetochores during mitosis, as compared with control-treated cells. Similarly, Nup133 RNAi leads to mitotic HeLa cells with reduced levels of both Nup133 and ELYS (red, and Insets) at the kinetochore. Numbers indicate the percentage of reduction of fluorescent intensities compared with those in the control RNAi transfections. (B) A large proportion of ELYS-depleted cells contain a midbody (arrowhead). (Scale bar: 10 μm.) (C) Percentage of cells with a midbody. Quantitation of the number of cells found in cytokinesis shows a significant increase in the occurrence of cells with midbody microtubules after ELYS and Nup133 RNAi, demonstrating a temporal block at this stage of the cell cycle, in comparison with transfections with the control siRNA duplex. (D) Two potential models for ELYS function. In the first model, ELYS serves as a core structural protein of the nuclear pore, one required for formation of the structure of nuclear pores. In the second model, ELYS is a nuclear pore-associated targeting protein that recruits Nups, such as the Nup107–160 complex, to assemble nuclear pores at the chromatin periphery. In its absence, pores would not be found at the nuclear rim.