Understanding the role of nuclear myosin in the spatial organisation of transcription

基因表达的调控对健康生活至关重要。基因表达是生物学中最基本的过程之一。在真核细胞中，RNA聚合酶II(RNAPII)引导遗传信息流从DNA到mRNA。详细的遗传和生化分析揭示了转录的多水平调节，包括一般转录因子、激活因子和抑制因子。这发生在基因的远端和近端，通过物理的相互作用。细胞对刺激的反应需要许多基因的协调和有效的调节。虽然人们普遍认为基因表达存在时间调控，但最近提出空间调控的报道有所增加。转录的空间组织已经争论和研究了三十多年。RNAPII簇的形成使远端基因组能够接触，同时增加了局部酶的浓度，从而提高了效率。我们已经确定基于肌动蛋白的分子马达，肌球蛋白VI，在转录启动方面是这个空间组织的关键调节因子。我们以前的工作表明，肌球蛋白VI直接与RNAPII结合，并能与DNA结合。我们目前的工作揭示了肌球蛋白VI通过在转录位点持有RNAPII来帮助转录启动的组织。肌球蛋白VI ATPase活性的丧失会导致RNAPII组织的破坏和基因表达的减少。我们现在希望了解肌球蛋白VI在这一角色中是如何调节的，以及这种影响在整个转录周期(如伸长过程中)中的广泛程度。这些发现将是理解转录的空间组织以及疾病和衰老过程中如何发生扰动的基础。这也可能揭示开发治疗策略的途径。我们将使用最先进的单分子成像技术进行这项工作。这种跨学科的方法将使我们能够直接解决肌球蛋白VI的调控与基因表达的关系。

The regulation of gene expression is essential for healthy living. Gene expression is one of the most fundamental processes in biology. In eukaryotic cells, RNA polymerase II (RNAPII) directs the flow of genetic information from DNA to mRNA. Detailed genetic and biochemical assays have revealed a multi-level regulation of transcription, including the general transcription factors, activators and repressors. This occurs both distal and proximal to the gene through physical interactions.A cell's response to stimulus requires coordinated and efficient regulation of many genes. While it is widely accepted there is temporal regulation of gene expression, more recently there has been an increase in reports proposed spatial regulation. The spatial organization of transcription has been debated and studied for over three decades. The formation of RNAPII clusters enables distal genomic contacts while increasing the local concentration of enzymes, which enhances efficiency. We have identified the actin-based molecular motor, myosin VI, as a critical regulator of this spatial organisation with respect to transcription initiation. Our previous work has revealed that myosin VI directly binds RNAPII and it can bind DNA. Our current work has revealed that myosin VI has the ability to aid the organisation of transcription initiation by holding RNAPII at transcription sites. The loss of inhibition of myosin VI ATPase activity leads to disruption of RNAPII organisation and a reduction in gene expression.We now wish to understand how myosin VI is regulated in this role and how widespread this effect is throughout the transcription cycle (e.g. during elongation). These findings will be fundamental for understanding the spatial organisation of transcription and how perturbation may occur during disease and aging. This may also reveal routes for developing therapeutic strategies.We will perform this work using state-of-the-art single molecule imaging techniques. This interdisciplinary approach will allow us to directly address how regulation of myosin VI related to gene expression.