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

描述（由申请人提供）：TRP通道是多种动物各种感觉系统中必要的信号成分。在TRP相关基因中，PKD1和PKD2是常染色体显性多囊肾病的两个主要致病基因。我们最近发现了两个pkd样蛋白PKD1L3和PKD2L1，作为哺乳动物味觉接收功能的候选酸受体。PKD1L3和PKD2L1在味觉受体细胞的一个子集中共同表达，与那些具有苦味、甜味或鲜味（咸味）化学物质受体的味觉细胞不同。我们发现PKD1L3和PKD2L1形成一个蛋白复合物，PKD1L3和PKD2L1的共表达对于它们的功能性细胞表面表达是必要的。最后，我们的数据表明，当在异源细胞中共表达时，PKD1L3和PKD2L1被各种酸激活，但不被其他种类的味觉化学物质、渗透压或机械流动激活，这表明PKD1L3和PKD2L1作为酸味受体起作用。基于这些和其他发现，我们提出以下项目来阐明PKD家族成员的体内功能。首先，我们将产生PKD1L3和PKD2L1基因敲除小鼠。我们已经完成了PKD2L1的基因敲除载体的创建，并且我们正处于创建PKD1L3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味觉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肾病（ADPKD）是一种遗传性疾病，有两个主要致病基因PKD1和PKD2。最近，我们已经确定了两个pkd样蛋白PKD1L3和PKD2L1作为酸受体在哺乳动物的味觉接收中起作用。我们的研究与公众的相关性在于，它将揭示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发展的方法

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