Two Birds with One Stone— Dealing with Nuclear Transport and Spindle Assembly

Spindle assembly and nuclear transport both utilize the same simple device: Ran-GTP-sensitive interaction of importin β and its cargo proteins. In this issue of Cell, Blower et al. (2005) report that one of these cargos required for spindle assembly turns out to be Rae1, previously known as an mRNA export protein. This study reveals the importance of RNAs in spindle structure