Nuclear transport and transcriptional regulation

Studies over the past 10 years have provided major insights into the molecu lar mechanisms responsible for active transport of macromolecules in and ou t of the nucleus. Nucleocytoplasmic transport pathways correspond to active and signal-mediated processes that involve substrates, adaptors and recept ors. Regulation of both nuclear import and nuclear export is mainly exerted at the level of transport complex formation and has emerged as one of the most efficient mechanisms to adapt gene expression to the cell environment by restricting the access of transcriptional regulators to their target gen es. (C) 1999 Federation of European Biochemical Societies.