The in vivo roles of PKD1L3 and PKD2L1 in sour taste detection

描述(由申请人提供)：Trp通道是不同动物物种各种感官系统中的必要信号成分。在Trp相关基因中，PKD1和PKD2是常染色体显性遗传性多囊肾病的两个主要致病基因。我们最近发现了两个类似PKD的蛋白，PKD1L3和PKD2L1，它们是哺乳动物酸味受体的候选蛋白，在味觉接受中发挥作用。PKD1L3和PKD2L1在味觉感受器细胞亚群中共表达，不同于那些具有苦味、甜味或鲜味(风味)化学物质受体的味觉细胞。我们发现，PKD1L3和PKD2L1形成了一个蛋白质复合体，PKD1L3和PKD2L1的共表达是其功能细胞表面表达所必需的。最后，我们的数据表明，当PKD1L3和PKD2L1在异种细胞中共表达时，可以被各种酸激活，但不能被其他味觉化学物质、渗透压或机械流动激活，这表明PKD1L3和PKD2L1作为酸味受体发挥作用。基于这些和其他发现，我们提出了以下项目来阐明PKD家族成员的体内功能。首先，我们将产生PKD1L3和PKD2L1的基因敲除小鼠。我们已经完成了PKD2L1的基因敲除载体的创建，我们正在为PKD1L3创建基因敲除载体的最后一步。其次，我们将开始分析PKD1L3和PKD2L1在酸味检测中的作用。我们将通过组织学检查、味觉神经记录和行为品尝测试来分析纯合子和杂合子转基因小鼠。第三，我们将产生PKD1L3和PKD2L1双基因敲除小鼠。常染色体显性遗传性多发性肾病(ADPKD)是一种具有两个主要致病基因的遗传性疾病，即PKD1和PKD2。最近，我们发现了两个类似PKD的蛋白，即PKD1L3和PKD2L1，它们是在哺乳动物的味觉感受中起作用的酸受体。我们的研究与公众的相关性在于，它将阐明PKD相关蛋白如何作为细胞外刺激的传感器发挥作用，并可能有助于开发一种防止ADPKD发生的方法

DESCRIPTION (provided by applicant): TRP channels are implicated as necessary signaling components in various sensory systems of diverse animal species. Among TRP related genes, PKD1 and PKD2 are two major causative genes for autosomal dominant polycystic kidney disease. We have recently identified two PKD-like proteins, PKD1L3 and PKD2L1, as candidate mammalian sour receptors functioning in taste reception. PKD1L3 and PKD2L1 are coexpressed in a subset of taste receptor cells distinct from those taste cells having receptors for bitter, sweet or umami (savory) tasting chemicals. We found that PKD1L3 and PKD2L1 form a protein complex and coexpression of PKD1L3 and PKD2L1 is necessary for their functional cell surface expression. Finally, our data indicated that when coexpressed in heterologous cells, PKD1L3 and PKD2L1 are activated by various acids, but not by other classes of taste chemicals, osmolarity, or mechanical flow, suggesting that PKD1L3 and PKD2L1 function as sour taste receptors. Based on these and other findings, we propose the following projects to elucidate the in vivo function of the PKD family members. First, we will generate gene knockout mice for PKD1L3 and PKD2L1. We have completed creating a gene knockout vector for PKD2L1 and we are at the final step in creating a gene knockout vector for PKD1L3. Second, we will start analyzing the function of PKD1L3 and PKD2L1 in sour taste detection. We will analyze the homozygous and heterozygous transgenic mice using histological examinations, gustatory nerve recordings and behavioral taste tests. Third, we will generate PKD1L3 and PKD2L1 double gene knockout mice. Autosomal dominant polycistic kidney disease (ADPKD) is a genetic disorder with two major causative genes, PKD1 and PKD2. Recently we have identified two PKD-like proteins, PKD1L3 and PKD2L1, as acid receptors functioning in taste reception in mammals. The relevance of our studies to the public is that it will shed light on how PKD related proteins function as sensors for extracellular stimuli and may help develop a way to prevent ADPKD from being developed