拟南芥组蛋白变体H2A.Z特异分子伴侣AtChz1的功能研究

H2A.Z is a highly conserved histone variant across all eukaryotes and has been demonstrated to participate in multiple key biological processes including gene transcription, DNA repair, cell cycle and development. ATP-dependent chromatin remodeling complexes and histone chaperones are responsible for H2A.Z deposition or removal to regulate the dynamic changes of the chromatin structure. In plants, the functions of H2A.Z and its related chromatin remodeling complexes are just beginning to be unveiled, while H2A.Z specific chaperones have not been identified so far. For many years, the applicant’s lab has been searching for the molecular mechanisms how the dynamic changes of chromatin regulate plant development and environmental plasticity. Recently, we found that the Arabidopsis thaliana homologues of yeast Chz1, AtChz1A and AtChz1B, act as the specific chaperones for H2A.Z, associate directly with the chromatin of key flower genes FLC, MAF4 and MAF5 in a H2A.Z-dependent manner, vice versa, loss of AtChz1A/B also impairs the enrichment of H2A.Z on these genes. Loss-of-function of AtChz1A/B causes the plants an early flowering phenotype resulting from the down-regulation of those negative key flower regulators. AtChz1A/B can interact with the ATP-dependent chromatin remodeling complex SWR1, and the deletion of AtChz1A/B results the genome-wide decrease of H2A.Z enrichment on the chromatin. We will try to analyze the biological function of AtChz1 using the techniques of biochemistry, genetics and bioinformatics. We also hope to provide new information to understand the roles of different histone chaperones and chromatin remodeling complexes in chromatin structure and plant development.

H2A.Z是一类在真核生物中高度保守的组蛋白变体，已有的研究表明H2A.Z参与转录调控、DNA损伤修复、细胞周期进程以及个体发育等重要的生物学过程，而ATP依赖的染色质重塑复合体和组蛋白分子伴侣共同负责H2A.Z在染色质上的掺入及移除，进而动态调控染色质的结构,而植物中的相关研究还非常有限。申请人实验室围绕染色质结构动态变化调节植物生长发育以及环境适应性的分子机制，对组蛋白分子伴侣的功能进行了长期研究。最新的研究发现：H2A.Z特异的分子伴侣AtChz1能够与开花关键负调控基因FLC、 MAF4和MAF5直接结合，影响这些靶基因上H2A.Z的富集程度及其表达，进而调解拟南芥的开花时间；AtChz1还可以与SWR1染色质重塑复合体结合，影响H2A.Z在拟南芥全基因组的分布。本项目将利用生物化学、遗传学、生物信息学等研究手段，深入分析植物组蛋白变体H2A.Z特异分子伴侣AtChz1的生理功能，

申请人实验室围绕染色质结构动态变化调节植物生长发育以及环境适应性的分子机制，对组蛋白分子伴侣的功能进行了长期研究。H2A.Z是一类在真核生物中高度保守的组蛋白变体，已有的研究表明H2A.Z参与转录调控、DNA损伤修复、细胞周期进程以及个体发育等重要的生物学过程，而ATP依赖的染色质重塑复合体和组蛋白分子伴侣共同负责H2A.Z在染色质上的掺入及移除，进而动态调控染色质的结构，但是植物中的相关研究还非常少。本项目的研究发现：组蛋白分子伴侣AtChz1能够特异结合组蛋白变体H2A.Z，而且可以直接结合开花关键负调控基因FLC、 MAF4和MAF5，影响这些靶基因上H2A.Z的富集程度及基因表达，进而调解拟南芥的开花时间；AtChz1还可以与SWR1染色质重塑复合体结合；通过ChIP-seq分析，比较了不同组蛋白分子伴侣和染色质重塑因子对H2A.Z在拟南芥全基因组分布的影响。本项目利用生物化学、遗传学、生物信息学等研究手段，深入分析了植物组蛋白变体H2A.Z特异分子伴侣AtChz1的生理功能，探索了不同组蛋白分子伴侣和染色质重塑因子对植物染色质结构及生长发育的影响。