Transcriptional regulation at the nuclear pore complex.

The nonrandom spatial distribution of chromosomes and genes in the eukaryotic nucleus has been appreciated for decades, although a detailed understanding of the functional role of such positioning has remained illusive. The most prominent structural feature of the nucleus is the nuclear periphery, classically considered as a zone of gene repression caused by the presence of heterochromatin and silencing factors. However, several recent studies have uncovered dynamic associations between nuclear pore complexes embedded in the nuclear membrane and actively transcribed genes. These interactions, mediated by DNA, RNA and proteins, add an additional level of control to eukaryotic gene expression. The existence of a peripheral transcriptional activation zone in the nucleus suggests that the spatial organization of the genome plays a significant role in transcriptional regulation.