Subnuclear dynamics and transcription factor function

At a simplistic level, the nucleus can be thought of as singular organelle with a nuclear envelope designed to isolate the biochemical reactions requi red for gene transcription and DNA replication from the cytoplasm. It has b ecome increasingly clear, however, that many higher levels of organization exist within the nucleus. A functional consequence of this organization is that nuclear processes that include transcription, RNA processing, and DNA synthesis are isolated to specific intranuclear domains to ensure efficienc y. With the advent of GFP technologies and increasingly sophisticated instr umentation, we have continued to dissect the relationship between organizat ion and function, in particular using live cells and ligand-dependent stero id receptors as a model system. These new opportunities have provided furth er insight into receptor function and the dependence upon intranuclear dyna mics that take place within minutes of hormone addition. (C) 2001 Wiley-Lis s, Inc.