Role of Conventional Myosin MYH9 in Hearing

传统肌球蛋白 MYH9 在听力中的作用

• 批准号: 6894723
• 负责人: Anil K Lalwani
• 金额: $ 42.25万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-07-05 至 2007-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6894723
• 关键词: actins; adenosinetriphosphatase; alleles; cell line; clinical research; congenital deafness; disease /disorder model; gene expression; gene mutation; gene targeting; genetically modified animals; genotype; growth /development; hearing; human genetic material tag; human subject; human tissue; laboratory mouse; labyrinth; molecular pathology; myosins; phenotype; protein protein interaction; protein structure function; transfection

DESCRIPTION (provided by applicant): Through the candidate gene approach, we have identified MYH9 as the causative gene responsible for DFNA17, an autosomal dominant nonsyndromic form of hereditary hearing impairment. MYH9, a conventional nonmuscle myosin, joins the growing list of myosins associated with hearing loss. In the DFNA17 family, a G to A transition at nucleotide 2114 changes codon 705 from an invariant arginine (R) to histidine (H), R705H, within a highly conserved SHI linker region. The co-segregation of the mutant MYH9 with nonsyndromic hearing impairment illustrates a biologically significant role for MYH9 in hearing and an organ-specific pathology associated with the mutant allele.The objective of the proposed research is to understand the role of MYH9 and its mutant allele MYH9R7O5H in hearing and its dysfunction. We will test the hypothesis that MYH9 is essential for normal hearing and that the mutant allele MYH9R7O5H leads to myosin dysfunction and auditory impairment. Initially, we will assess the importance of MYH9 to hearing in humans. Individuals with hearing loss of unknown genetic etiology will be screened for alterations in the MYH9 gene to determine the contribution of MYH9 mutations in nonsyndromic hearing impairment. The discovery of additional mutations will facilitate genotype-phenotype correlation and determining the contribution of MYH9 to hearing loss in general. Secondly, we will assess the role of MYH9 in inner ear development and hearing. This will be carried out by characterizing the expression pattern of Myh9 in the developing and an adult mouse inner ear and determining the effects of its absence. We will use the XA1 36 ES cell line carrying a marker gene insertion into its Myh9 allele to generate mice transgenic for the Myh9 null allele. Thirdly, we will assess the effect of the MYH9R7O5H mutation on myosin function in vitro and in vivo. MYH9R7O5H will be characterized in vitro for its ATPase activity, actin-dependent motility and the effect of its expression in cultured cell lines in which biological role of MYH9 has been established. Generating a mouse model of DFNA1 7 through targeted or random germline introduction of Myh9R7O5H allele will assess the effect of MYH9R7O5H in vivo. In summary, the proposed research will lead to elucidation of the role of MYH9 in hearing and deafness.

描述（由申请人提供）：通过候选基因方法，我们已确定 MYH9 是 DFNA17 的致病基因，DFNA17 是一种常染色体显性非综合征形式的遗传性听力障碍。 MYH9 是一种传统的非肌肉肌球蛋白，它加入了与听力损失相关的越来越多的肌球蛋白行列。在 DFNA17 家族中，在高度保守的 SHI 接头区域内，核苷酸 2114 处的 G 到 A 转变将密码子 705 从不变的精氨酸 (R) 更改为组氨酸 (H)，即 R705H。突变体 MYH9 与非综合征性听力障碍的共分离说明了 MYH9 在听力中的重要生物学作用以及与突变等位基因相关的器官特异性病理学。本研究的目的是了解 MYH9 及其突变等位基因 MYH9R7O5H 在听力及其功能障碍中的作用。我们将检验以下假设：MYH9 对于正常听力至关重要，并且突变等位基因 MYH9R7O5H 会导致肌球蛋白功能障碍和听觉障碍。首先，我们将评估 MYH9 对人类听力的重要性。将筛查遗传病因不明的听力损失个体的 MYH9 基因改变，以确定 MYH9 突变对非综合征性听力障碍的影响。其他突变的发现将促进基因型-表型相关性并确定 MYH9 对一般听力损失的影响。其次，我们将评估 MYH9 在内耳发育和听力中的作用。这将通过表征发育中和成年小鼠内耳中 Myh9 的表达模式并确定其缺失的影响来进行。我们将使用在其 Myh9 等位基因中插入标记基因的 XA1 36 ES 细胞系来生成 Myh9 无效等位基因的转基因小鼠。第三，我们将评估 MYH9R7O5H 突变对体外和体内肌球蛋白功能的影响。 MYH9R7O5H 将在体外表征其 ATP 酶活性、肌动蛋白依赖性运动及其在已确定 MYH9 生物学作用的培养细胞系中表达的效果。通过定向或随机种系引入 Myh9R7O5H 等位基因生成 DFNA1 7 小鼠模型，将评估 MYH9R7O5H 的体内作用。总之，拟议的研究将阐明 MYH9 在听力和耳聋中的作用。