The unfolded protein response as a mechanism for cellular identity in the developing olfactory system

未折叠蛋白反应作为发育中嗅觉系统细胞身份的机制

• 批准号: 10266117
• 负责人: Hani John Shayya
• 金额: $ 4.65万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-15 至 2024-09-14
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10266117
• 关键词: Affect; Alleles; Axon; Bar Codes; Binding; Biological Models; Cell surface; Cells; ChIP-seq; DNA; Data; Disease; Environment; Ephrin-A5; Event; Extracellular Space; Feedback; Genes; Genetic; Genetic Identity; Genetic Processes; Genetic Translation; Health; Individual; Ligands; Link; Location; Logic; Mammals; Maps; Mediating; Molecular; Molecular Genetics; Mus; Nervous system structure; Neurons; Neuropilin-1; Neuropilin-2; Olfactory Epithelium; Olfactory Pathways; Pattern; Positioning Attribute; Process; Proteins; Regulation; Regulatory Element; Reporter; Reporting; Reproducibility; Rest; Role; Semaphorin-3A; Semaphorins; Shapes; Specific qualifier value; Stereotyping; Stress; Testing; Translating; Translational Regulation; Translations; Work; axon guidance; comparative; experience; experimental study; genetic approach; genome-wide; in vivo; mouse genetics; mouse genome; neural circuit; neurodevelopment; neuron development; novel; olfactory bulb; olfactory receptor; olfactory sensory neurons; programs; receptor; receptor expression; relating to nervous system; response; ribosome profiling; spatiotemporal; stress state; transcription factor; transcriptome sequencing

PROJECT SUMMARY In neural development, genetic programs endow each neuron with a distinct cellular identity. This identity includes a repertoire of molecules on the cell surface that dictate how that neuron will respond to the environment it encounters as it projects to form neural circuits. A large body of work has focused on how the interactions between cell surface identity molecules and ligands in the extracellular space guide neural projections, yet it remains comparatively unclear how mammals generate the stunning diversity of neuronal identities that underly these intricate networks of connectivity. The mammalian olfactory system offers a perfect microcosm of this question. Here, developing olfactory sensory neurons (OSN) chose to express a single olfactory receptor (OR) from roughly 1,500 possibilities in the mouse genome. OR choice sets the components of OSN cellular identity that direct targeting, endowing an OSN with a “barcode” of cell surface molecules that specifies a precise location in the olfactory bulb (OB) to which all cells choosing that OR will project. The composition of this barcode is known and includes neural activity-independent molecules (Neuropilin-1/Semaphorin-3A, Neuropilin- 2/Semaphorin-3F) as well as activity-dependent molecules (Kirrel2-3, Ephrin-A5 and its receptor, non-canonical Protocadherins). However, the mechanisms mapping OR choice to a specific identity barcode are incompletely understood. We previously reported that OR choice during OSN development triggers the unfolded protein response (UPR), a genome-wide mRNA translation-regulatory program essential for complete neuronal maturation and stable OR expression. Preliminary data suggests that the UPR is differentially active in OSNs depending on the OR that they chose. Remarkably, these differences are intimately linked to expression patterns for several neuronal activity-dependent components of the OSN cell surface axon targeting barcode, as well as three transcription factors with possible roles in organizing the barcode. These results suggest an entirely novel role for the UPR as a molecular determinant of neuronal identity in the context of axon guidance. We will test this hypothesis in three specific aims. In aim 1, we will use two mouse genetic approaches to demonstrate that differential activation of the UPR causally affects OSN cellular identity and axon targeting. Aim 2 will define the molecular cascade linking the UPR to these identity molecules by identifying master regulator transcription factors (mrTFs) controlling UPR-mediated cellular identity. Finally, aim 3 will determine how hierarchical OR-dependent and OR-independent roles for the UPR work together to shape the whole of OSN identity. We anticipate that these experiments will unveil a previously undescribed role for the UPR as a molecular determinant of neuronal identity relevant for axon guidance in the olfactory system, offering a new paradigm with which to study neural development in the context of health and disease.

项目摘要 在神经元发育中，遗传程序赋予每个神经元具有独特的细胞身份。这个身份 包括细胞表面上分子的曲目，决定神经元如何对环境做出反应 当它计划形成神经回路时，它会遇到。大量工作集中于互动方式 在细胞表面身份分子和细胞外空间中的配体之间指导神经项目，但 仍然不清楚哺乳动物如何产生令人惊叹的神经元身份的多样性 这些复杂的连接网络。哺乳动物嗅觉系统提供了完美的缩影 问题。在这里，开发嗅觉感觉神经元（OSN）选择表达单个嗅觉受体（OR） 从小鼠基因组中大约1,500种可能性。或选择设置OSN蜂窝身份的组件 直接靶向，赋予OSN具有细胞表面分子的“条形码”，以指定精度位置 在所有细胞选择或将投射到的嗅球（OB）中。该条形码的组成是 已知并包括神经活动非依赖性分子（Neuropilin-1/Semaphorin-3a，Neuropilin-- 2/Semaphorin-3F）以及活性依赖性分子（Kirrel2-3，Ephrin-A5及其受体，非典型 协议）。但是，映射或选择特定身份条形码的机制不完全 理解。我们先前报道说，OSN开发期间的选择会触发展开的蛋白质 响应（UPR），全基因组mRNA翻译 - 调节程序对于完整神经元必不可少 成熟，稳定或表达。初步数据表明UPR在OSN中具有差异性活性 取决于他们选择的或。值得注意的是，这些差异与表达模式密切相关 对于OSN细胞表面轴突靶向条形码的几个神经元活性依赖性成分以及 三个转录因子在组织条形码中可能作用。这些结果表明一个完全新颖的 在轴突引导的背景下，UPR作为神经元认同确定的分子的作用。我们将测试 这是三个特定目标的假设。在AIM 1中，我们将使用两种鼠标遗传方法来证明 UPR的差异激活会影响OSN细胞身份和轴突靶向。 AIM 2意志 通过识别主调节剂来定义将UPR连接到这些身份分子的分子级联 控制UPR介导的细胞身份的转录因子（MRTF）。最后，AIM 3将确定 UPR的分层或独立角色如何共同塑造整体 OSN身份。我们预计这些实验将推出以前未描述的UPR角色 一种分子确定的与嗅觉系统中轴突引导相关的神经元身份，提供了新的 在健康和疾病背景下研究神经发育的范式。