Diversity in nucleocytoplasmic transport pathways.

Significant progress has been made toward our understanding of the basic principle of nucleocytoplasmic transport, and the structure of transport factors, as well as the diversity of nucleocytoplasmic transport pathways. This review outlines the current knowledge of transport, and discusses the problems that remain as to how eukaryotic cells acquire additional levels for the regulation of gene expression from a diversity of nucleocytoplasmic transport pathways.