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），一种异聚体六亚基蛋白 复杂，是DNA复制所必需的。ORC的功能也超越了DNA 复制的最小的ORC亚基，Orc 6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，Orc 6有一个额外的 通过与septin复合物相互作用在胞质分裂中起作用，septin复合物是一种高度保守的 聚合蛋白质组装，这对许多物种的胞质分裂至关重要， 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Orc 6的结构，并确定了其结构特征， 直接影响蛋白质在复制和胞质分裂中的功能。我们的特点 Orc 6不同结构域的突变导致Meier-Gorlin综合征（MGS）， 人类，一种常染色体隐性遗传疾病，特征为原始侏儒症， 发育异常我们发现，尽管不同的潜在分子 这些突变导致相似的表型，前RC缺陷， 形成和受损的DNA复制。因此，Orc 6的多种分子功能 可以实验性地解剖，以获得其离散的完整理解。 细胞中的角色。本提案的总体目标是界定不同的机制， 的后生动物Orc 6功能的DNA复制和胞质分裂使用果蝇作为一个 模型系统。我们建立了一个基于Orc 6的人源化果蝇模型系统 这将被用来分析自然发生的和结构导向的影响， 人Orc 6蛋白功能的靶向突变。监管见解， ORC在后生动物中的复制和非复制功能是有限的， 几十年的研究。我们完成这个项目将有助于填补这一空白， 了解不同的ORC在后生动物中的功能，并提供线索， 特定突变或错误调节将导致生长和发育缺陷。