Evolution and diversity of synaptic transmission: Roles for voltage-gated calcium channels and PDZ-domain mediated scaffolding

突触传递的进化和多样性：电压门控钙通道和 PDZ 域介导的支架的作用

• 批准号: RGPIN-2016-06023
• 负责人: Senatore, Adriano
• 金额: $ 2.26万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=710098
• 关键词: Evolution; diversity; synaptic; transmission; Roles

Synaptic transmission lies at the very core of nervous system function. In my research, I seek to understand how synaptic structure and function differs between distantly-related animals, and how the synapse evolved. Indeed, gaining a deep, phylogenetic understanding of the synapse and its evolution will help broaden our understanding of this complex and dynamic cell-cell signaling apparatus, basic science that can help guide future efforts to treat diseases of the nervous system involving deficiencies in synaptic transmission. Interestingly, recent genome sequencing studies have revealed that early-diverging “primitive” animals that lack nervous systems, such as the small marine invertebrate Trichoplax adhaerens, harbour a majority of genes required for synaptic transmission. Also interesting is that the most early-diverging animals known, ctenophores such as Mnemiopsis leidyi, bear nervous systems and synaptic transmission that appears to have evolved independently. My broad background in molecular biology, electrophysiology and genomics/transcriptomics uniquely positions me and my personnel to exploit these animals for gaining insights into synaptic diversity and evolution. Over this 5 year NSERC grant, my team and I will explore these subjects by completing the following objectives: 1) Objective 1: Comparative structure-function and physiology studies of voltage-gated calcium (Cav) channels, which play crucial roles in synaptic transmission and are implicated in numerous human diseases. We will compare human and other invertebrate Cav channels with highly divergent orthologues/homologues from Trichoplax and Mnemiopsis, to gain general insights into conserved and defining biophysical features of each Cav channel type, and to determine whether the roles that Cav channels play in Trichoplax and Mnemiopsis resemble known synaptic functions of Cav channels in other well-studied organisms. 2) Objective 2: High-throughput proteomics to evaluate if key protein-protein interactions that underlie synaptic scaffolding, including the association of Cav channels with pre-synaptic neurotransmitter secretion, are absent in Trichoplax, in accordance with its lack of synapses, and to define the molecular architecture of the independently evolved and poorly understood synapses of Mnemiopsis. 3) Objective 3: The absence of synapses in Trichoplax, and the independently evolved ones of Mnemiopsis, should be reflected by absences/differences in key synaptic protein-protein interactions. We will use information gathered from objectives 1 and 2 to inform in vivo rescue experiments in the fruit fly Drosophila, using wildtype vs. “in vitro evolved” synaptic genes from Trichoplax and Mnemiopsis with introduced protein interaction domains, to test hypotheses about key molecular innovations that might have facilitated synapse evolution.

突触传递是神经系统功能的核心。在我的研究中，我试图了解突触结构和功能在远亲动物之间的差异，以及突触是如何进化的。事实上，获得对突触及其进化的深入的系统发育理解将有助于拓宽我们对这种复杂而动态的细胞-细胞信号装置的理解，基础科学可以帮助指导未来治疗涉及突触传递缺陷的神经系统疾病的努力。 有趣的是，最近的基因组测序研究表明，早期分化的缺乏神经系统的“原始”动物，如小型海洋无脊椎动物粘毛虫，拥有突触传递所需的大部分基因。同样有趣的是，已知的最早分化的动物，栉水母，如Mnemiopsis leidyi，具有神经系统和突触传递，似乎是独立进化的。我在分子生物学，电生理学和基因组学/转录组学方面的广泛背景使我和我的工作人员能够利用这些动物来深入了解突触多样性和进化。在这5年的NSERC补助金，我的团队和我将通过完成以下目标来探索这些主题： 1)目标一：电压门控钙通道（Cav）在突触传递中起着重要作用，与许多人类疾病有关。我们将比较人类和其他无脊椎动物的Cav通道与Trichoplax和Mnemiopsis的高度分歧的直系同源物/同源物，以获得一般的见解保守和定义的生物物理特征的每个Cav通道类型，并确定是否Cav通道在Trichoplax和Mnemiopsis中发挥的作用类似于已知的突触功能的Cav通道在其他研究良好的生物体。 2)目标二：高通量蛋白质组学，以评估关键的蛋白质-蛋白质相互作用，突触支架的基础，包括关联的Cav通道与突触前神经递质分泌，是不存在的Trichoplax，根据其缺乏突触，并定义独立进化和了解甚少的突触的Mnemiopsis的分子结构。 3)目标三：在Trichoplax的突触的情况下，和独立进化的Mnemiopsis，应该反映在关键的突触蛋白质-蛋白质相互作用的缺席/差异。我们将使用从目标1和2收集的信息，以告知在果蝇的体内救援实验，使用野生型与“体外进化”的突触基因从Trichoplax和Mnemiopsis与引入蛋白质相互作用域，以测试假设的关键分子创新，可能促进突触进化。