Chromatin higher order dynamics: A single molecule approach

真核生物染色体的高阶结构是由蛋白质/DNA相互作用调控的，这种相互作用介导DNA折叠成染色质纤维。染色质纤维结构围绕核小体，染色质的基本单位。SNF2 atp酶和组蛋白修饰酶重塑核小体，并在细胞周期和个体发育过程中在表观遗传密码的产生、维持和改变中发挥关键作用。我们建议研究染色质重塑因子对染色质纤维物理性质的影响。为此，将产生适合物理化学表征的完全重组模型多核体阵列。其次，确定的原型染色质重塑活性将以制备量纯化。最后，将采用最先进的单分子磁镊子和延时原子力显微镜来严格研究染色质重塑剂催化的染色质高阶结构转变的物理性质和动力学。通过这种多学科结合的方法，我们期望以无与伦比的分辨率阐明核小体介导的高阶染色质结构转变。

Higher order structure of eukaryotic chromosomes is governed by protein/DNA interactions that mediate the folding of DNA into chromatin fibres. Chromatin fibre structure revolves around nucleosomes, the fundamental units of chromatin. SNF2 ATPases and histone modifying enzymes remodel nucleosomes and have been documented to play key roles in the generation, maintenance and alteration of the epigenetic code during the cell cycle and during ontogeny. We propose to study the influence of chromatin remodelling factors on the physical properties of chromatin fibres. To this end, fully recombinant model polynucleosomal arrays suited for physico-chemical characterisation will be generated. Second, defined prototypic chromatin remodelling activities will be purified in preparative quantities. Last, state-of-the-art single molecule magnetic tweezers and time-lapse Atomic Force Microscopy will be employed to rigorously investigate the physical properties and dynamics of chromatin higher order structural transitions catalysed by chromatin remodellers. With this combined multidisciplinary approach we expect to elucidate nucleosome mediated higher order chromatin structural transitions with an unsurpassed degree of resolution.