DNA Replication and Cytokinesis.

DNA 复制和细胞分裂。

• 批准号: 10550052
• 负责人: IGOR N CHESNOKOV
• 金额: $ 6.5万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-18 至 2028-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10550052
• 关键词: Basal Cell Nevus Syndrome; Biological Models; Cell Cycle; Cells; Complex; Cytokinesis; Cytoskeleton; DNA biosynthesis; Defect; Development; Disease; Drosophila genus; Dwarfism; Eukaryota; Goals; Growth; Human; Impairment; Molecular; Mutation; Normal Cell; Phenotype; Pre-Replication Complex; Protein Complex Subunit; Proteins; Research; Role; Structure; autosome; insight; origin recognition complex; protein function

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 metazoan 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。 起源识别复合物 (ORC)，一种异聚六亚基蛋白 复杂，对于 DNA 复制至关重要。 ORC的功能也超越了DNA 复制。最小的 ORC 亚基 Orc6 蛋白对 DNA 非常重要 在所有真核生物中复制。我们已经证明，在果蝇中 Orc6 有一个额外的 通过与 septin 复合物相互作用在胞质分裂中发挥作用，septin 复合物是高度保守的 聚合蛋白组装对许多物种的胞质分裂至关重要，并且是 被认为是细胞骨架的重要组成部分。在初步研究中我们 解析了人类 Orc6 的结构并确定了其结构特征，这些特征有助于 直接影响蛋白质在复制和胞质分裂中的功能。我们表征 Orc6 不同结构域的突变导致 Meier-Gorlin 综合征 (MGS) 人类，一种以原始侏儒症为特征的常染色体隐性遗传疾病 发育异常。我们表明，尽管潜在的分子不同 这些突变导致相似的表型、pre-RC 缺陷的机制 形成和DNA复制受损。因此，Orc6 的多种分子功能 可以通过实验剖析以获得对其离散的完整理解 在细胞中的作用。该提案的总体目标是定义不同的机制 使用果蝇作为后生动物 Orc6 在 DNA 复制和胞质分裂中的功能 模型系统。我们建立了基于Orc6的人源化果蝇模型系统 它将用于分析自然发生和结构引导的影响 人类 Orc6 蛋白质功能的靶向突变。监管见解 尽管ORC在后生动物中的复制和非复制功能有限 数十年的研究。该项目的完成将有助于填补我们的这一空白。 了解 ORC 在后生动物中的不同功能，并提供关于如何 特定的突变或错误调节会导致生长和发育缺陷。