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

基本信息

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
项目类别：
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

项目摘要

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.

项目概要在神经发育中，遗传程序赋予每个神经元独特的细胞身份。包括细胞表面的一系列分子，这些分子决定神经元如何响应环境它在形成神经回路时遇到的情况大量的工作都集中在如何相互作用上。细胞表面身份分子和细胞外空间中的配体之间的相互作用引导神经投射，但它目前仍相对不清楚哺乳动物如何产生神经元身份的惊人多样性这些复杂的连接网络提供了一个完美的缩影。在这里，发育中的嗅觉感觉神经元（OSN）选择表达单一嗅觉受体（OR）。小鼠基因组中大约 1,500 种可能性的 OR 选择决定了 OSN 细胞身份的组成部分。直接靶向，赋予 OSN 细胞表面分子的“条形码”，指定精确位置在嗅球 (OB) 中，所有选择该 OR 的细胞都将投射该条形码的组成。已知，包括神经活动独立分子（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、非规范然而，将 OR 选择映射到特定身份条形码的机制并不完整我们之前报道过 OSN 发育过程中的 OR 选择会触发未折叠的蛋白质。响应（UPR），一种对完整神经元至关重要的全基因组 mRNA 翻译调节程序成熟和稳定的 OR 表达表明 UPR 在 OSN 中具有不同的活性。取决于他们选择的 OR 值得注意的是，这些差异与表达模式密切相关。用于 OSN 细胞表面轴突靶向条形码的几个神经活动依赖性组件，以及三种可能在组织条形码中发挥作用的转录因子这些结果表明了一种全新的方法。我们将测试 UPR 作为轴突引导背景下神经身份的分子决定因素的作用。在目标 1 中，我们将使用两种小鼠遗传方法来证明这一假设。 UPR 的差异激活会因果性地影响 OSN 细胞身份和轴突 Aim 2 的靶向。通过识别主调节器来定义将 UPR 与这些身份分子连接起来的分子级联最后，目标 3 将决定控制 UPR 介导的细胞身份的转录因子 (mrTF)。 UPR 的分层 OR 依赖型和 OR 独立型角色如何共同塑造整体我们预计这些实验将揭示 UPR 之前未描述过的作用：与嗅觉系统中轴突引导相关的神经身份的分子决定因素，提供了一种新的方法在健康和疾病背景下研究神经发育的范式。