The role of Orc6 in DNA replication and cytokinesis.

Orc6 在 DNA 复制和胞质分裂中的作用。

• 批准号: 10458042
• 负责人: IGOR N CHESNOKOV
• 金额: $ 33.41万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10458042
• 关键词: Address; Amino Acids; Basal Cell Nevus Syndrome; Binding; Biochemical; Biological Models; Cell Cycle; Cell Cycle Progression; Cells; Cellular biology; Complex; Cytokinesis; Cytoskeleton; DNA; DNA Binding; DNA biosynthesis; DNA replication origin; Data; Defect; Development; Dimerization; Disease; Drosophila genus; Dwarfism; Electron Microscopy; Eukaryota; Filament; Genes; Goals; Growth; Guanosine Triphosphate Phosphohydrolases; Human; Impairment; In Vitro; Lead; Length; Licensing; Link; MCM2 gene; Modeling; Molecular; Molecular Genetics; Mutagenesis; Mutation; Nature; Normal Cell; Organism; Peptide Initiation Factors; Phenotype; Polymers; Positioning Attribute; Pre-Replication Complex; Process; Protein Complex Subunit; Proteins; Regulation; Replication Origin; Research; Role; Site; Structure; Translating; base; cell growth; dimer; experimental study; fly; genetic approach; helicase; in vitro testing; in vivo; insight; mutant; origin recognition complex; polymerization; protein function; recruit

Abstract. The Origin Recognition Complex (ORC), a heteromeric six-subunit protein complex, is essential for DNA replication. ORC's functions also extend beyond DNA replication. The smallest of ORC subunits, Orc6 protein, is important for DNA replication in all eukaryotes. We have shown that in Drosophila Orc6 has an additional role in cytokinesis through interaction with the septin complex, a highly conserved polymerizing protein assembly that is critical for cytokinesis in many species and is recognized as important component of the cytoskeleton. In preliminary studies we solved the structure of human Orc6 and identified its structural features that contribute directly to the functions of the protein in replication and cytokinesis. We characterized the mutations in different domains of Orc6 leading to Meier-Gorlin syndrome (MGS) in humans, an autosomal recessive disorder characterized by primordial dwarfism and developmental abnormalities. We showed that despite different underlying molecular mechanisms these mutations resulted in similar phenotypes, defects in pre-RC formation and impaired DNA replication. Thus, the diverse molecular functions of Orc6 can be experimentally dissected to obtain a complete understanding of its discrete roles in the cell. The overall goal of this proposal is to define the distinct mechanisms of Orc6 function in DNA replication and in cytokinesis using Drosophila as a model system. We established a humanized Orc6-based Drosophila model system which will be used to analyze the effects of naturally occurring and structure-guided targeted mutations of human Orc6 in protein functions. Regulatory insights into replicative and non-replicative functions of ORC in metazoans are limited, despite decades of research. Our completion of this project will help to fill this gap in our understanding of diverse ORC's functions in metazoans and provide clues as to how a specific mutation or mis-regulation would lead to growth and developmental defects.

抽象的。 原始识别络合物（ORC），一种异质体六亚基蛋白 复杂，对于DNA复制至关重要。兽人的功能也超出了DNA 复制。最小的兽人亚基ORC6蛋白对于DNA很重要 在所有真核生物中复制。我们已经表明，果蝇中有一个额外的 通过与Septin复合物相互作用，在细胞因子中的作用，这是一种高度保守的 聚合蛋白质组件对于许多物种中的细胞因子至关重要，IS 被认为是细胞骨架的重要组成部分。在初步研究中 解决了人类ORC6的结构，并确定了其贡献的结构特征 直接达到蛋白质在复制和细胞因子中的功能。我们表征了 ORC6不同域的突变导致Meier-Gorlin综合征（MGS） 人类，一种以原始矮人为特征的常染色体隐性疾病和 发育异常。我们表明，尽管有不同的分子 这些突变的机制导致了相似的表型，PRE-RC的缺陷 形成和DNA复制受损。因此，ORC6的分子函数多样 可以在实验上进行剖析以完全了解其离散 在细胞中的作用。该提案的总体目标是定义不同的机制 使用果蝇作为模型，在DNA复制和细胞因子中的ORC6功能 系统。我们建立了一个基于人性化的ORC6果蝇模型系统 用于分析天然发生和结构引导的靶向效果 蛋白质功能中人ORC6的突变。对复制性和 尽管数十年 研究。我们完成该项目的完成将有助于填补这一空白 多样化的兽人在后生动物中的功能，并提供有关特定突变的线索 或错误调节会导致增长和发育缺陷。