Functional subnuclear partitioning of transcription factors

After many years of reductionistic approaches to characterize molecular mechanisms involved in transcription, the number of factors recognized to take part in this process has increased remarkably and continues to grow. When considering posttranslational modifications in conjunction with the large number of factors involved in modulating the activity of transcription complex components, the overall intricacy becomes staggering. After two decades of intensive molecular investigations, there has been a concerted effort to integrate these findings with cellular approaches to understand transcription on a more global level. This sort of reasoning actually revisits studies of approximately 20 years ago that considered the functional consequences of steroid receptor association with nuclear structure. With an abundance of new molecular probes and increasingly powerful instruments to detect them in fixed and, more recently, live cells, the issue of functional subnuclear organization is receiving increased attention. In this report, we focus on advances in characterizing the functional significance of transcription factor association with the nucleoskeleton. In particular, we consider recent biochemical and "molecular morphology" data that point to the importance of dynamic spatial and solubility partitioning of gene regulators with nuclear architecture.