Role of CDYL in translating histone modification patterns for chromatin organization and regulation

真核细胞中所有基因组过程的模板是染色质。组蛋白的翻译后修饰（PTM）-除了DNA，染色质的主要成分-被认为是调节染色质结构和功能的关键。对组蛋白PTM的分子工作机制的机械见解对于理解表观遗传学的生物化学是必不可少的，表观遗传学是控制基因组读出的调控途径。组蛋白H3在赖氨酸9处的甲基化（H3 K9 me 3）被认为是异染色质的标志之一。在以前的工作中，我们已经确定了CDYL作为一种新的蛋白质特异性地识别这种组蛋白PTM。虽然CDYL已被证明具有转录抑制活性-可能通过与阻遏物复合物的瞬时相互作用介导-但关于CDYL的染色质调节功能尚不清楚。初步分析表明，CDYL作为H3 K9 me 3染色质相互作用蛋白在体内和体外。此外，CDYL的丢失影响非洲爪蟾胚胎的发育。在这个项目中，我们将分析CDYL的染色质分布与基因组和组蛋白PTM的关系-特别是H3 K9 me 3。我们将鉴定和分析CDYL相关的蛋白质至关重要的CDYL染色质调控。将使用生物化学和生物物理方法研究CDYL复合物对染色质构象和组织的影响。最后，将在非洲爪蟾模型系统中分析CDYL-H3 K9 me 3相互作用对染色质调控的生物学意义。

The template of all genomic processes in eukaryotic cells is chromatin. Post-translational modifications (PTM) of histone proteins – besides DNA, the major constituents of chromatin – are thought to be key in regulating chromatin structure and function. Mechanistic insights into the molecular working mechanisms of histone PTMs are essential for understanding the biochemistry of epi-genetics, that is regulatory pathways which govern the readout of the genome. Methylation of histone H3 at lysine 9 (H3K9me3) is considered one of the hallmarks of heterochromatin. In previous work, we have identified CDYL as a novel protein specifically recognizing this histone PTM. While CDYL has been shown to possess transcriptional repressive activity – likely mediated through a transient interaction with a repressor complex – nothing is known regarding the chromatin regulatory function of CDYL. Preliminary analysis shows CDYL as an H3K9me3 chromatin interacting protein in vivo and in vitro. Moreover, loss of CDYL affects developmental of Xenopus laevis embryos. In this project, we will analyze the chromatin distribution of CDYL in relation to the genome and in respect to histone PTMs – especially H3K9me3. We will identify and analyze CDYL associated proteins essential for CDYL chromatin regulation. Effects of CDYL complexes onto chromatin conformation and organization will be investigated using biochemical and biophysical methods. Lastly, the biological significance of CDYL-H3K9me3 interaction for chromatin regulation will be analyzed in the Xenopus laevis model system.