The nuclear pore complex:: a jack of all trades?

The nuclear pore complex (NPC) is the only gateway between the cell nucleus and the cytoplasm, and it mediates all movement between these two compartments. The past few years have witnessed much progress on its structure and molecular architecture, its interaction with soluble transport receptors, and how nucleocytoplasmic transport is regulated by the small GTPase Ran. However, the exact molecular mechanisms underlying nucleocytoplasmic transport and in particular cargo translocation through the NPC are understood only poorly. Recent findings on the interaction between the NPC and transport factors might provide insights into how efficient NPC translocation is accomplished. Moreover, in addition to mediating nucleocytoplasmic transport, the NPC seems to be involved, either directly or indirectly, in many other cellular processes such as chromosome segregation, gene expression, the secretory pathway and apoptosis. Here we review recent findings on these unexpected roles of the NPC.