MOLECULAR GENETICS OF TOPOSOMES EUCARYOTES

真核生物拓扑体的分子遗传学

• 批准号: 3295755
• 负责人: HANS NOLL
• 金额: $ 15.06万
• 依托单位: UNIVERSITY OF HAWAII AT MANOA
• 依托单位国家: 美国
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-01-01 至 1992-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3295755
• 关键词: DNA replication; Drosophilidae; affinity chromatography; antibody; antibody neutralization test; binding proteins; biological information processing; blastema; cell adhesion; cell cell interaction; cell growth regulation; cell population study; chemical binding; complementary DNA; contact inhibition; cytogenetics; early embryonic stage; embryo /fetus cell /tissue; enzyme linked immunosorbent assay; eukaryote; gel electrophoresis; gene expression; genetic mapping; genetic regulation; glycoproteins; immunoglobulins; immunoprecipitation; laboratory mouse; laboratory rabbit; ligands; macromolecule; membrane proteins; molecular cloning; molecular genetics; monoclonal antibody; nonmammalian vertebrate embryology; nucleic acid hybridization; nucleic acid probes; nucleic acid sequence; oligonucleotides; protein biosynthesis; protein sequence; receptor; saltwater environment; sea urchins; surface antigens; tissue /cell culture

This project is concerned with the molecular basis of pattern formation in embryogenesis. The generation and maintenance of patterns in multicellular organisms requires the integration of four basic functions: (i) mechanical linkage between cells, (ii) positional guidance, (iii) control of DNA replication, and (iv) control of cell movement and shape. The project proposes that all of these functions are vested in one large multifunctional macromolecular assembly of which the toposome, a large oligomeric glycoprotein complex, is the cell surface component entrusted with mediating cell adhesion and expressing positional information. The central idea is that toposomes belongs to the general class of cell surface signal molecules that includes such well known glycoprotein complexes as the receptors for insulin, epidermal growth factor and receptors of the immune system. Toposomes share with these other receptors an extracellular binding domain recognizing a protein ligand, except that the ligand is the cognate portion of another toposome on a different cell. Toposomes are presumably bound to an integral membrane receptor that appears to be highly conserved and related to the fibronectin receptor. We further postulate that this receptor has a cytoplasmic signal generating domain, analogous to EPG and the family of membrane-bound proto-oncogenes, and a binding site for components of the cytoskeleton. The toposome concept will be tested by experiments that examine its predictions. Sequencing of the toposome genes that have been cloned for the sea urchin and Drosophila will have high priority. Other experiments are aimed at isolating peptides with the activity of the contact site and its characterization with monoclonal antibodies. These results will be combined with in situ labeling experiments of the developing embryo to deduce the positional code. involvement of toposomes in transduction of signals for DNA replication will be tested by blocking the contact site with ligands that restore DNA synthesis in dissociated cells of sea urchin embryos. Toposomes are thought to be key molecules in tumorigenesis because they would explain for the first time why in cancer loss of contact inhibition, positional guidance (leading to invasiveness) and cytoskeletal order are always linked.

该项目涉及模式的分子基础 胚胎发生过程中的形成。 的生成和维护 多细胞生物的模式需要整合 四个基本功能：（i）细胞之间的机械连接，（ii） 位置引导，(iii) DN​​A 复制的控制，以及 (iv) 控制细胞的运动和形状。 该项目建议所有 这些功能都归属于一个大型多功能 大分子组装体，其中拓扑体，一个大的 寡聚糖蛋白复合物，是细胞表面成分 负责介导细胞粘附并表达位置 信息。 中心思想是拓扑体属于 细胞表面信号分子的一般类别，包括 众所周知的糖蛋白复合物作为胰岛素受体， 表皮生长因子和免疫系统受体。 拓扑体与这些其他受体共享细胞外 识别蛋白质配体的结合域，除了 配体是不同拓扑体上的同源部分 细胞。 拓扑体可能与完整的膜结合 受体似乎高度保守并与 纤连蛋白受体。 我们进一步假设该受体具有 细胞质信号生成域，类似于 EPG 和 膜结合原癌基因家族，以及一个结合位点 细胞骨架的组成部分。 拓扑体概念将通过实验进行检验 它的预测。 已测序的拓扑体基因 克隆海胆和果蝇将具有高度优先权。 其他实验旨在分离肽 接触部位的活性及其特征 单克隆抗体。 这些结果将与 对发育中的胚胎进行原位标记实验来推断 位置代码。 拓扑体参与转导 DNA复制信号将通过阻断接触来测试 具有恢复解离细胞中 DNA 合成的配体的位点 海胆胚胎。 拓扑体被认为是关键分子 在肿瘤发生中，因为他们将第一次解释 为什么癌症会失去接触抑制、位置引导 （导致侵袭性）和细胞骨架顺序总是相关的。