Nuclear trafficking in health and disease.

In eukaryotic cells, the cytoplasm and the nucleus are separated by a double-membraned nuclear envelope (NE). Thus, transport of molecules between the nucleus and the cytoplasm occurs via gateways termed the nuclear pore complexes (NPCs), which are the largest intracellular channels in nature. While small molecules can passively translocate through the NPC, large molecules are actively imported into the nucleus by interacting with receptors that bind nuclear pore complex proteins (Nups). Regulatory factors then function in assembly and disassembly of transport complexes. Signaling pathways, cell cycle, pathogens, and other physiopathological conditions regulate various constituents of the nuclear transport machinery. Here, we will discuss several findings related to modulation of nuclear transport during physiological and pathological conditions, including tumorigenesis, viral infection, and congenital syndrome. We will also explore chemical biological approaches that are being used as probes to reveal new mechanisms that regulate nucleocytoplasmic trafficking and that are serving as starting points for drug development.