TMC gene function in sensory hair cells

TMC 基因在感觉毛细胞中的功能

• 批准号: 8598696
• 负责人: JEFFREY R HOLT
• 金额: $ 37.19万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-07-01 至 2018-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8598696
• 关键词: Alleles; Amino Acids; Antibodies; Auditory; Binding; Biological Assay; C-terminal; Cell physiology; Cells; Code; Complex; Data; Elements; Epitopes; Equilibrium; Foundations; Functional disorder; Future; Gene Family; Genes; Genetic; Goals; Hair Cells; Hearing; Hearing Impaired Persons; Human; Knockout Mice; Labyrinth; Mammals; Molecular; Mus; Mutant Strains Mice; Mutation; Patients; Permeability; Play; Property; Proteins; Relative (related person); Research; Role; Scientist; Sensorineural Hearing Loss; Sensory; Sensory Hair; Series; Solid; Stereocilium; Structure; Vestibular Hair Cells; Work; base; cellular transduction; deafness; design; gene function; hearing impairment; insight; interest; member; mutant; neuronal cell body; novel; paralogous gene; polypeptide; public health relevance; research study; trafficking

DESCRIPTION (provided by applicant): Mutations in transmembrane channel-like gene 1 (TMC1) underlie dominant, progressive hearing loss (DFNA36) and recessive nonsyndromic sensorineural hearing loss (DFNB7/B11) in humans (Kurima et al., 2002). Similarly, semidominant and recessive alleles of Tmc1 cause hearing loss in Beethoven (Bth) and deafness (dn) mutant mice (Vreugde et al.,2002; Kurima et al., 2002). Tmc1 is a member of the Tmc gene family that includes seven other paralogs in mammals (Keresztes et al., 2003). Tmc1 and closely related Tmc2 are expressed in auditory and vestibular hair cells of the mouse inner ear. We have recently demonstrated that mice that lack Tmc1 and Tmc2 are deaf and suffer profound vestibular dysfunction. The data suggest that Tmc1 and Tmc2 are essential for normal hair cell function but their precise molecular function remains elusive. TMC1 and TMC2 proteins may be components of the cell body required for folding or trafficking of transduction molecules, they may function as linker proteins, mechanically in series with the mechanotransduction channel or they may be pore-forming subunits of the hair cell transduction channel itself. To investigate possible TMC functions we have designed a systematic and comprehensive research strategy that will allow us to distinguish amongst these various hypotheses. We will begin with a thorough biophysical characterization of the properties of hair cell transduction in mutant mice that express either Tmc1 or Tmc2 alone. Next, we will introduce mutant and chimeric forms of Tmc1 and/or Tmc2 into hair cells that lack both genes. Our previous work (Kawashima et al., 2011) demonstrated rescue of mechanotransduction in hair cells of Tmc1/Tmc2 knockout mice transfected with wild-type Tmc1 or Tmc2. Therefore, we predict that similar experiments with mutant Tmc genes will provide a novel platform for structure/function studies in native hair cells which will allow us to identify the function of TMC proteins. Lastly, e will localize TMC proteins in hair cells of Tmc1/Tmc2 knockout mice transfected with wild-type and mutant TMC constructs fused to short polypeptide epitope tags. Immunolocalization with antibodies specific to the epitope tag will provide localization data superior to that currently available. Taken together, the data that emerge from the proposed studies will help identify the function of TMC proteins in hair cells and may support their role as components of the hair cell transduction apparatus.

描述（由申请人提供）：跨膜通道样基因1（TMC 1）中的突变是人类显性、进行性听力损失（DFNA 36）和隐性非综合征感音神经性听力损失（DFNB 7/B11）的基础（Kurima et al.，2002年）。类似地，Tmc 1的半显性和隐性等位基因导致贝多芬（Bth）和耳聋（dn）突变小鼠的听力损失（Vreugde et al.，2002; Kurima等人，2002年）。Tmc 1是Tmc基因家族的成员，该家族包括哺乳动物中的七种其他旁系同源物（Keresztes et al.，2003年）。Tmc 1和密切相关的Tmc 2在小鼠内耳的听觉和前庭毛细胞中表达。我们最近已经证明，缺乏Tmc 1和Tmc 2的小鼠是耳聋的，并且患有严重的前庭功能障碍。这些数据表明，Tmc 1和Tmc 2是正常毛细胞功能所必需的，但其精确的分子功能仍然难以捉摸。TMC 1和TMC 2蛋白可以是转导分子折叠或运输所需的细胞体的组分，它们可以作为接头蛋白，与机械转导通道机械串联，或者它们可以是毛细胞转导通道本身的孔形成亚基。为了研究可能的TMC功能，我们设计了一个系统和全面的研究策略，使我们能够区分这些不同的假设。我们将开始与一个彻底的生物物理特性的毛细胞转导的突变小鼠表达Tmc 1或Tmc 2单独。接下来，我们将Tmc 1和/或Tmc 2的突变体和嵌合体形式引入缺乏这两种基因的毛细胞中。我们以前的工作（Kawashima等人，2011）证明了在用野生型Tmc 1或Tmc 2转染的Tmc 1/Tmc 2敲除小鼠的毛细胞中机械转导的拯救。因此，我们预测，类似的实验与突变Tmc基因将提供一个新的平台，在天然毛细胞的结构/功能的研究，这将使我们能够确定TMC蛋白的功能。最后，e将定位TMC蛋白在Tmc 1/Tmc 2敲除小鼠的毛细胞中，所述小鼠用融合至短多肽表位标签的野生型和突变型TMC构建体转染。用对表位标签特异的抗体进行免疫定位将提供优于目前可用的定位数据的定位数据上级。总之，从拟议的研究中出现的数据将有助于确定TMC蛋白在毛细胞中的功能，并可能支持它们作为毛细胞转导装置的组成部分的作用。