New perspectives on nuclear transport.

A central aspect of cellular function is the proper regulation of nucleocytoplasmic transport. In recent years, significant progress has been made in identifying and characterizing the essential components of the transport machinery. Despite these advances, some facets of this process are still unclear. Furthermore, recent work has uncovered novel molecules and mechanisms of nuclear transport. This review focuses on the unresolved and novel aspects of nuclear transport and explores issues in tRNA, snRNA, and mRNA export that highlight the diversity of nuclear transport mechanisms.