Transcriptome profiling of sour taste cells

描述（由申请人提供）：大多数脊椎动物对五种基本味道有反应：甜、苦、鲜、酸和咸，每一种味道都提供了摄入食物的营养成分和安全性的独特信息。五种味觉品质中的每一种都由不同的味觉细胞子集检测，这些细胞表达不同的受体和信号分子。虽然在理解调节苦、甜、鲜味和咸味的分子和途径方面取得了巨大进展，但对酸味的了解相对较少。检测酸味的细胞被证明是通过TRP离子通道PKD2L1的表达来定义的，但是PKD2L1基因本身对于酸味是必不可少的，并且对酸味的感觉反应背后的离子机制仍然知之甚少。在最近的工作中，我们使用Pkd2l1启动子驱动黄色荧光蛋白（YFP）的小鼠，发现酸味细胞表达一种新的质子电导，有助于对酸的反应。当前提案的具体目标是确定编码这种质子电导的基因。为此，我们提出两个具体目标。在目标1中，我们将使用深度测序对yfp标记的酸细胞进行转录分析，我们将鉴定在Pkd2l1细胞中富集的转录本，并可能编码新的跨膜蛋白。在Aim 2中，我们将在异种细胞类型中表达最佳候选细胞，并通过膜片钳记录确定它们是否产生质子通道。这种质子通道的识别将是理解味觉系统的重要一步，并可能有助于定义一类新的离子通道。味觉是人类和其他生物调节其摄食行为的重要方式，因此味觉信号的关键分子成分的鉴定可以直接影响人类的健康和福祉。

DESCRIPTION (provided by applicant): Most vertebrate species are responsive to five basic tastes: sweet, bitter, umami, sour and salty, each of which provides unique information on the nutritional content and safety of ingested food. Each of the five taste qualities is detected by a distinct subset of taste cells, which express distinct receptors and signaling molecules. While great progress has been made in understanding the molecules and pathways that mediate bitter, sweet, umami and salty tastes, relatively little is known about sour taste. The cells that detect sour taste have been shown to be defined by expression of the TRP ion channel PKD2L1, but the Pkd2l1 gene itself is dispensable for sour taste and the ionic mechanisms that underlie sensory responses to sour remain poorly understood. In recent work, using a mouse in which yellow fluorescent protein (YFP) was driven by the promoter of Pkd2l1, we showed that sour taste cells express a novel proton conductance which contributes to the response to acids. The specific goal of the current proposal is to identify the gene that encodes this proton conductance. To do this, we propose two specific aims. In aim 1, we will use deep sequencing to perform transcription profiling of YFP-tagged sour cells and we will identify transcripts that ae enriched in Pkd2l1 cells and are likely to encode novel transmembrane proteins. Under Aim 2, we will express the top candidates in a heterologous cell type and determine with patch clamp recording whether they generate a proton channel. The identification of this proton channel will represent an important step in understanding the taste system, and may help define a new class of ion channels. Taste is an essential way in which humans and other organisms regulate their ingestive behavior and the identification of key molecular components of taste signaling can therefore have a direct impact on human health and well-being.