The Unfolded Protein Response as an Organizer of Chemosensory Response

未折叠的蛋白质反应作为化学感应反应的组织者

• 批准号: 8891400
• 负责人: Stavros Lomvardas
• 金额: $ 33.66万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2019-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8891400
• 关键词: Adenylate Cyclase; Alleles; Animals; Antibodies; Biochemical; Biochemical Genetics; Biological Models; Cells; ChIP-seq; Chemoreceptors; Co-Immunoprecipitations; Communication; Custom; Data; Disease; Employee Strikes; Family; Feedback; G-Protein-Coupled Receptors; Gene Family; Genetic; Genetic Transcription; Health; In Vitro; Incubated; Knockout Mice; Ligands; Maps; Mediating; Molecular; Molecular Chaperones; Mus; Nature; Nervous system structure; Neurons; Nuclear; Odorant Receptors; Olfactory Epithelium; Open Reading Frames; Pathway interactions; Peptide Initiation Factors; Peptides; Phosphotransferases; Physiological; Play; Process; Production; Protein Isoforms; Proteins; Publishing; Receptor Gene; Regulation; Role; Series; Signal Pathway; Signal Transduction; Stress; Testing; Time; Transcriptional Activation; Transgenic Mice; Translating; Translation Initiation; Translations; Up-Regulation; Wild Type Mouse; activating transcription factor; arm; attenuation; base; genetic analysis; histone demethylase; in vivo; insight; novel; olfactory receptor; olfactory sensory neurons; prevent; receptor; receptor expression; research study; response; transcription factor; transcriptome sequencing

DESCRIPTION (provided by applicant): Olfactory receptor (OR) choice, the transcriptional activation of one out of thousands of available mammalian OR alleles is a poorly understood process. We previously demonstrated that in response to OR translation, the ER-resident kinase Perk phosphorylates the translation initiation factor eif2a, eliciting a signal that culminates in the stabilization of OR choice. Genetic experiments suggest that this feedback signal depends upon the transient but general attenuation of translation and the specific upregulation of translation of the nuclear isoform of transcription factor ATF5. Production of nuclear ATF5 enhances the transcription of Adenylyl cyclase 3 (Adcy3), which relieves the OR-induced ER stress and represses the expression of histone demethylase LSD1, allowing the terminal differentiation of olfactory neurons and making the expression of the chosen OR permanent. These observations pose significant questions regarding the molecular principles of this signaling pathway. Here, we propose experiments that seek to provide answers to these questions and to offer mechanistic insight into this novel use of the unfolded protein response pathway. Specifically, we propose biochemical and genetic experiments aiming to reveal whether OR proteins interact directly with Perk and to map the exact peptides responsible for Perk activation. Furthermore, we aim to elucidate the mechanism of action of ATF5 as transcriptional regulator and to explore the function of two distinct nuclear isoforms that, according to our preliminary genetic analysis, play different roles in the regulation of OR choice and the differentiation of olfactory neurons. Finally, we propose experiments that aim to dissect the concluding step of this signaling pathway, which is the relief of ER stress and the termination of OR-induced Perk signaling. Timely termination of this arm of the unfolded protein response is as critical for the stabilization of OR expression as the initiation of this pathway an we hypothesize that OR-specific chaperones play a critical role in preventing OR-Perk interactions in the ER. Genetic and biochemical experiments will reveal the identity of these proteins and examine their role in the OR-elicited feedback. Our experiments will provide novel insight into a process that has remained enigmatic since the discovery the largest mammalian gene family and will reveal regulatory principles that likely apply to many other chemoreceptor families mediating communication with the outside world.

描述（由申请人提供）：嗅觉受体（OR）选择，成千上万可用的哺乳动物或等位基因中一种中一个的转录激活是一个鲜为人知的过程。我们先前证明，在响应或翻译时，ER居民激酶PERK磷酸化了翻译起始因子EIF2A，引发了一个信号，该信号最终导致或选择。遗传实验表明，该反馈信号取决于翻译的瞬时但一般的衰减以及转录因子核同工型ATF5核同工型翻译的特定上调。核ATF5的产生增强了腺苷酸环化酶3（ADCY3）的转录，从而缓解了OR诱导的ER应力并抑制组蛋白脱甲基酶LSD1的表达，从而使嗅觉神经元的最终分化并使所选或永久性的表达表达。这些观察结果提出了有关该信号通路的分子原理的重大问题。在这里，我们提出了试图为这些问题提供答案的实验，并提供了对展开的蛋白质反应途径这种新颖使用的机械洞察力。具体而言，我们提出了旨在揭示或蛋白质是否与PERK相互作用并绘制负责PERK激活的确切肽的生化和遗传实验。此外，我们旨在阐明ATF5作为转录调节剂的作用机理，并探索两种不同的核同工型的功能，根据我们的初步遗传分析，这些功能在调节或选择和嗅觉神经元的分化中起不同的作用。最后，我们提出了旨在剖析此信号通路的结论步骤的实验，这是ER应力的缓解和OR诱导的PERK信号的终止。及时终止展开的蛋白质反应对稳定或表达至关重要，就像该途径的启动一样，我们假设或特异性的伴侣在防止ER中的Or-Perk相互作用中起关键作用。遗传和生化实验将揭示这些蛋白质的身份，并检查它们在或引起人们的反馈中的作用。自从发现最大的哺乳动物基因家族以来，我们的实验将提供有关一个杂乱无章的过程的新洞察力，并将揭示可能适用于许多其他化学感受器家族的监管原理，从而调解与外界的交流。