Regulation of Odorant Receptor Gene Expression

气味受体基因表达的调控

• 批准号: 8119757
• 负责人: PAUL FEINSTEIN
• 金额: $ 33.86万
• 依托单位: HUNTER COLLEGE
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-06 至 2015-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8119757
• 关键词: Adult; Alleles; Applications Grants; Binding; Binding Proteins; Binding Sites; Biological Assay; Brain; Cell division; Cells; Chemicals; Choices and Control; Code; Collaborations; DNA; DNA Binding; DNA-Binding Proteins; Detection; Development; Elderly; Elements; Environment; Epithelium; Event; Failure; Food; Food Poisoning; Funding; Gene Expression; Gene Family; Generations; Genes; Genetic; Genetic Polymorphism; Genomics; Goals; Health; Homeodomain Proteins; Human; Human body; In Vitro; Incidence; Individual; Integral Membrane Protein; Journals; LHX2 gene; Lead; Mammals; Manuscripts; Mentors; Mentorship; Molecular; Mus; Mutation; Nasal Epithelium; Nature; Neurons; Nucleic Acid Regulatory Sequences; Nucleotides; Odorant Receptors; Odors; Olfactory Epithelium; One-Step dentin bonding system; Organism; Pattern; Phase; Play; Population; Process; Production; Promoter Regions; Proteins; Publications; Receptor Gene; Regulation; Reporter; Resolution; Role; Scheme; Science; Scientist; Series; Signal Transduction; Smell Perception; System; Testing; Translating; Uterus; Variant; Work; Writing; cell type; enhancer binding protein; feeding; food consumption; genetic element; genetic manipulation; homeodomain; in vivo; insight; mammalian genome; meetings; neural circuit; novel strategies; prevent; promoter; protein purification; public health relevance; receptor; research study; stem cell population; transcription factor

DESCRIPTION (provided by applicant): The olfactory system is able to recognize thousands of odorants thus maintaining food consumption in humans. The ability to identify odors by humans is dependent on odorant receptors within olfactory neurons that line the nasal epithelium. This epithelium is under continuous cell division by a basal stem cell population that produces immature olfactory neurons, which then become mature olfactory neurons. Odorant receptors (ORs) are clonally expressed in immature olfactory neurons. The mammalian genome consists of ~1500 OR genes; these genes belong to the seven-transmembrane receptor superfamily. However, each allele of each gene is treated as a separate entity leading to ~3000 OR alleles to be expressed in a clonal (singular) manner by olfactory neurons. The ability for this singular OR allele expression is a multi-step manner. A critical step is the production of a functional OR protein. Olfactory neurons are found in domains within the epithelium such that a given olfactory neuron chooses (in general) between ~100 OR genes (~200 alleles). The selection process occurs in two-steps: one of ~200 alleles is chosen for expression (1st choice) within an immature neuron, followed by OR protein production, which is tested for functionality. Failure to produce a seven-transmembrane protein allows for the singular choice mechanism to choose another OR allele in that same immature olfactory neuron (2nd choice). If the chosen seven-transmembrane OR is unable to couple with the signal transduction machinery, then that olfactory neuron will fail to mature and die. The critical step in the expression of an OR gene is the initial choice of one OR allele within an immature neuron (1st choice). To date, it is completely unknown how this "singular choice" process occurs at a molecular level. Analysis of very small OR promoter regions (~300bp) have lead to the identification of two transcription factors that may play a role: an O/E-1 type binding protein and a homeodomain type biding protein. The identification of more candidate DNA binding proteins and their interactions is necessary to understand the "singular choice" process. This project fully exploits the small regulatory regions used to produce OR singular choice in immature olfactory neurons. In Aim 1, the most minimal OR control region will be defined in order to identify other candidate transcription factors. There are at least 10-15 different olfactory neuronal cell types each fated to express one of ~200 OR alleles. In Aim 2, two minimal OR promoters normally expressed in different olfactory cell types will be used to identify additional transcription factors. This will allow the understanding of how specific patterns within the olfactory epithelium are obtained. In Aim 3, a candidate homeodomain protein will be deleted within immature and/or mature neurons in order to determine its role on OR gene expression. In Aim 4, I will make every attempt to promote this work into publications and greater funding. PUBLIC HEALTH RELEVANCE: Gene expression is necessary for cells to function properly in the human body. The sense of smell is critically dependent on olfactory neurons that translate the chemical world to the brain. Olfactory neurons govern this odor recognition process through careful expression of odorant receptors. Loss of olfactory function leads to poor feeding in geriatric populations as well as higher incidence of food poisoning. Studying odorant receptor gene expression will give insights into how the olfactory system is put together and maintained throughout adulthood.

描述（由申请人提供）：嗅觉系统能够识别成千上万的气味，从而维持人类的食物消耗。人类鉴定气味的能力取决于鼻上皮细胞的嗅觉神经元内的气味受体。该上皮受到产生未成熟嗅觉神经元的基础干细胞群的连续细胞分裂，然后成为成熟的嗅觉神经元。气味受体（OR）在未成熟的嗅觉神经元中表达。哺乳动物基因组由〜1500或基因组成；这些基因属于七跨膜受体超家族。但是，每个基因的每个等位基因都被视为一个单独的实体，导致〜3000或通过嗅觉神经元以克隆（单数）方式表达的等位基因。这种单数或等位基因表达的能力是多步骤的方式。一个关键的步骤是产生功能或蛋白质。嗅觉神经元在上皮内的结构域中发现，因此给定的嗅觉神经元在〜100或基因之间选择（通常）（〜200等位基因）。选择过程以两个步骤发生：在未成熟的神经元内选择了〜200个等位基因之一，然后选择了或蛋白质的产生，该神经元的或蛋白质的产生。未能产生七跨膜蛋白，可以在相同的未成熟嗅觉神经元（第二选择）中选择奇异的选择机制。如果选择的七跨膜或无法与信号转导机械配对，那么嗅觉神经元将无法成熟并死亡。表达或基因表达的关键步骤是未成熟神经元内一个或等位基因的初始选择（第一选择）。迄今为止，这一“单一选择”过程是在分子水平上发生的。对非常小或启动子区域（〜300bp）的分析已导致对可能起作用的两个转录因子的鉴定：O/E-1型结合蛋白和同源域类型竞标蛋白。为了了解“单一选择”过程，必须鉴定更多候选DNA结合蛋白及其相互作用。该项目充分利用用于在未成熟嗅觉神经元中产生或单一选择的小规范区域。在AIM 1中，将定义最小或最小的控制区域，以识别其他候选转录因子。至少有10-15种不同的嗅觉神经元细胞类型，每个细胞类型都会表达〜200或等位基因之一。在AIM 2中，通常在不同的嗅觉细胞类型中表达的两个最小或启动子将用于识别其他转录因子。这将允许理解如何获得嗅觉上皮中的特定模式。在AIM 3中，为了确定其在基因表达或基因表达上的作用，将在未成熟和/或成熟的神经元中删除候选同源域蛋白。在AIM 4中，我将尽一切努力将这项工作促进出版物和更多资金。 公共卫生相关性：基因表达对于细胞在人体中正常运作所必需。嗅觉关键取决于将化学世界转化为大脑的嗅觉神经元。嗅觉神经元通过仔细表达气味受体来控制这种气味识别过程。嗅觉功能的丧失导致老年人群的进食不良以及食物中毒的发生率更高。研究气味受体基因表达将有见识如何在整个成年期整理和维持嗅觉系统。