Functional analysis of the atypical DSL protein DLL3

非典型DSL蛋白DLL3的功能分析

• 批准号: 5426277
• 负责人: Professor Dr. Achim Gossler
• 金额: --
• 依托单位: Institut für Molekularbiologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2004
• 资助国家: 德国
• 起止时间: 2003-12-31 至 2013-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5426277?language=en
• 关键词: Functional; analysis; atypical; DSL; protein

The Notch signaling pathway is an evolutionary conserved mechanism mediating the direct communication between adjacent cells. Notch signaling is pivotal for the regulation of multiple developmental processes in diverse organisms such as nematodes, insects and vertrebrates. Recent studies in vertebrate embryos have demonstrated an essential role for Notch signaling in somite formation and patterning. Disruption of Notch signaling causes severe defects during somitogenesis: boundaries are misaligned and irregular, somite polarity is abolished or perturbed, and segment borders are not maintained. Two of the five ligands for Notch in mouse, Delta1 (Dll1) and Delta3 (Dll3), have essential functions during somitogenesis. However, despite the largely overlapping expression of Dll1 and Dll3 in the presomitic mesoderm, null alleles of both Dll1 (Dll1lacZ) and Dll3 (Dll3pu) affect patterning processes in the presomitic mesoderm differently, suggesting that Dll1 and Dll3 have distinct, non-redundant functions during somite formation. In this study we propose to test the hypothesis that Dll1 and Dll3 have non-redundant functions especially during somitogenesis, and that the specific functions of Dll1 and Dll3 are brought about by different biochemical properties. This will be achieved by replacing Dll1 with the coding sequence of Dll3 and analysis of mice carrying this gene replacement, and biochemical characterization of the interaction of Dll1 and Dll3 with Notch receptors in vitro. These experiments should further elucidate the functions and biochemical properties of the Notch ligands Dll1 and Dll3 and help to understand their functions in the paraxial mesoderm and the basic molecular mechanisms underlying mesoderm segmentation in mammals.

Notch信号通路是一种进化保守的机制，调节相邻细胞之间的直接通讯。Notch信号在线虫、昆虫和脊椎动物等多种生物的多种发育过程的调控中起着关键作用。最近对脊椎动物胚胎的研究表明，Notch信号在体节形成和模式形成中起着重要作用。Notch信号的中断会导致体细胞发生过程中的严重缺陷：边界错位和不规则，体节极性被取消或扰乱，节段边界不能保持。在小鼠的5种Notch配体中，有两种是Delta1(Dll1)和Delta3(Dll3)，它们在体细胞发生过程中起着重要的作用。然而，尽管Dll1和Dll3在减数分裂前中胚层中的表达有很大的重叠，但Dll1(Dll1lacZ)和Dll3(Dll3Pu)的空等位基因对减数分裂前中胚层的构型过程有不同的影响，这表明Dll1和Dll3在体节形成过程中具有不同的、非冗余的功能。在本研究中，我们提出了一种假设，即DLL1和DLL3具有非冗余功能，特别是在体细胞发生过程中，并且DLL1和DLL3的特定功能是由不同的生化特性带来的。这将通过以下方式实现：用DLL3的编码序列替换DLL1，对携带该基因替换的小鼠进行分析，并在体外对DLL1和DLL3与Notch受体的相互作用进行生化表征。这些实验将进一步阐明Notch配体DLL1和DLL3的功能和生化特性，并有助于了解它们在哺乳动物中胚轴旁的功能和中胚层分割的基本分子机制。