Molecular Mechanisms of Olfactory Receptor Choice

描述(申请人提供)：哺乳动物嗅觉的敏感度和辨别能力来自于新的基因调控机制、细胞特化以及嗅觉系统的整体解剖和结构。遗传控制的关键方面之一是在每个感觉神经元中选择性地表达单个嗅觉受体(OR)基因的一个等位基因。过去在这一领域的研究已经证明了这一单受体单神经元的原理，并揭示了嗅觉受体蛋白在建立和维持这种关系的反馈中的重要作用。由于在转基因动物中检查这些过程所需的复杂性和努力，对这一调控过程的分子理解一直受到阻碍。包括我们自己在内的几个研究人员在转基因小鼠上的实验表明，受体编码序列在决定转录状态方面发挥了额外的关键作用。 感受器。在这项资助中，我们将使用分子和遗传学方法来阐明导致OR表达显着调节的机制。我们将检验这样的假设，即ORS蛋白编码区内的核酸序列在基因组、转录或翻译水平上控制功能表达，并且这一活动对于正确的OR表达是重要的。在具体目标1中，我们利用细胞培养模型来机械地研究和理解OR表达的一个方面。同时，我们建议确定OR编码序列中负责这一不寻常的调控过程的序列。在具体目标2中，我们将利用转基因小鼠在体内检查改变这一规则的后果。总之，这些实验可能会揭示基因调控的新机制。这项拟议的研究将结合新的表达系统和广泛的分子方法，系统地研究可能被其他生物系统共享的调控过程，阐明这些机制可能会为研究在人类健康和疾病中发挥关键作用的基因提供更多的洞察力。

DESCRIPTION (provided by applicant): The exquisite sensitivity and discrimination capabilities of mammalian olfaction arise from a combination of novel genetic regulatory mechanisms, cellular specializations, and the overall anatomy and architecture of the olfactory system. One of the key aspects of genetic control is the selective expression of one allele of a single olfactory receptor (OR) gene in each sensory neuron. Past research in this area has demonstrated this one-receptor one-neuron principle and revealed an important role for the olfactory receptor protein for feedback that establishes and maintains this relationship. A molecular understanding of processes underlying this regulation has been hampered by the complexity and effort required to examine these process in genetically modified animals. Experiments in transgenic mice by several investigators, including our own, have suggested an additional critical role for the receptor coding sequence in determining the transcription state of the receptor. In this grant we will use molecular and genetic approaches to elucidate mechanisms responsible for the remarkable regulation of OR expression. We will test the hypothesis that nucleic acid sequences within the protein coding regions of ORs control functional expression at the genomic, transcriptional or translational level and that this activityis important for proper OR expression. In specific aim 1, we utilize a cell culture model to investigate and understand mechanistically one aspect of OR expression. In parallel, we propose to determine the sequences within the OR coding sequence that are responsible for this unusual regulatory process. In specific aim 2, we will utilize genetically modified mice to examine the consequences of altering this regulation in vivo. Together, these experiments may reveal new mechanisms of gene regulation. The proposed research will incorporate novel expression systems and a broad array of molecular methods to systematically study a regulatory process that is likely to be shared by other biological systems Elucidating these mechanisms may provide additional insight in genes that play critical roles in human health and disease.