GIPC3, multifunctional myosin adaptor in mammalian auditory hair cells

GIPC3，哺乳动物听毛细胞中的多功能肌球蛋白适配器

基本信息

批准号：
10624964
负责人：
Gregory I Frolenkov
金额：
$ 55.7万
依托单位：
UNIVERSITY OF KENTUCKY
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-06-10 至 2025-05-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10624964
关键词：
Actins Adopted Affect Age Age Months Ankle Apical Architecture Auditory Auditory system Belief Binding Biochemical Biochemistry C-terminal CDH23 gene Cadherin Domain Cell physiology Cells Cellular Structures Complex Consensus Coupling Custom DLG4 gene Data Development Diameter Dimerization Endocytosis Epidermal Growth Factor Receptor Pathway Substrate 8 Family Family member Hair Hair Cells Hearing Height Human Inherited Inner Hair Cells Knowledge Label Labyrinth Link MYO7A gene Mechanics Mediating Molecular Motor Mouse Strains Mus Mutation Myosin ATPase N-terminal Outcome Study Patients Phenotype Physiological Point Mutation Positioning Attribute Prevention Protein Family Proteins Receptor Activation Reporting Rest Role Shapes Site Structure Surface Synaptic Transmission Therapeutic Time Ubiquitin Vesicle WHRN gene autosome cell type deaf deafness dimer hearing impairment in vivo insight live cell imaging mechanotransduction member mouse model mutant myosin VI myosin XVA nanobodies normal hearing novel prevent receptor receptor binding response structural biology therapy development trafficking two-photon uptake

项目摘要

GIPC3, a member of Gα-Interacting Protein, C-terminus (GIPC) family, is known to be essential for hearing. Eleven mutations in GIPC3, spread throughout its three structural domains, cause inherited autosomal recessive hearing loss. However, the molecular basis for GIPC3 function in the auditory system and the mechanisms by which these human mutations result in hearing loss are unknown. We have recently determined the structure of GIPC3 bound to a prototypical receptor and determined the molecular mechanism of GIPC3 activation and its subsequent binding to MYO6, the unconventional myosin that is expressed in the auditory hair cells and is essential for hearing. These biochemical and structural studies allowed us to predict the effects of known deafness-related mutations in GIPC3 on its activation and MYO6 binding. We have generated two new mouse models, one that is lacking functional GIPC3 and another one with a W301X point mutation in Gipc3 that corresponds to a mutation with the most severe auditory phenotype in humans. This study will explore the central hypothesis that GIPC3 has a dual role in the auditory hair cells. We hypothesize that in stereocilia GIPC3 is involved in shaping mechanotransduction and hair bundle structure through its interactions with CDH23/myosin-VIIa and myosin-XVa, respectively. In the cell body, GIPC3 is essential for apical endocytosis at the pericuticular neckless region due to its interaction with myosin-VI. All these functions are crucial for normal hearing. However, the exact molecular mechanisms that determine the resting tension in the mechanotransduc- tion machinery as well as gradation of stereocilia heights and diameters in the auditory hair cell bundles are still enigmatic. Likewise, very little is known about molecular mechanisms and even the role of pericuticular neckless endocytosis in the hair cell function. The expected outcomes of this study are to uncover (a) the precise mechanism of deafness associated with GIPC3 deficiency and (b) the physiological role of GIPC3 in hair cell functions, especially in mechanotransduction, formation of the hair bundle architecture, and endocytosis at the pericuticular neckless. Deciphering the function of GIPC3 protein and its known mutations is a critical step towards the development of therapies for the treatment and/or prevention of GIPC3-dependent deafness and hearing loss.

GIPC3是Gα相互作用蛋白C-末端（GIPC）家族的成员，已知对于听力。 GIPC3中的11个突变，分布在其三个结构域中，原因是继承常染色体隐性听力损失。但是，听觉中GIPC3功能的分子基础这些人类突变导致听力丧失的系统和机制尚不清楚。我们最近确定了与原型受体结合的GIPC3的结构，并确定了 GIPC3激活的分子机制及其随后与Myo6的结合，非常规在听觉毛细胞中表达的肌球蛋白对于听力至关重要。这些生化和结构研究使我们能够预测GIPC3中已知的死亡性突变对其的影响激活和Myo6结合。我们已经生成了两个新的鼠标模型，一种缺乏功能 GIPC3和另一个具有W301X点突变的GIPC3中的，该突变与与该突变相对应人类最严重的听觉表型。这项研究将探讨GIPC3具有的中心假设在听觉毛细胞中的双重作用。我们假设在Stereocilia中，GIPC3参与了塑造机械转导和发束结构通过其与CDH23/肌球蛋白-VIIA的相互作用和肌球蛋白-XVA。在细胞体中，GIPC3对于牙周牙齿的顶端内吞作用至关重要由于它与肌球蛋白-VI的相互作用，无颈区域。所有这些功能对于正常听力至关重要。然而，确定机械转换中静息张力的确切分子机制在听觉毛细胞束中的立体胶质高度和直径的电位机械以及渐变仍然是神秘的。同样，关于分子机制甚至作用的知之甚少明确无颈内吞作用。这项研究的预期结果是揭露（a）与GIPC3缺乏症相关的死亡的精确机制和（b） GIPC3在毛细胞功能中的生理作用，尤其是在机械转导，头发的形成中束结构和无颈无颈内的内吞作用。解密GIPC3的功能蛋白质及其已知突变是迈向疗法的关键一步和/或预防GIPC3依赖性死亡和听力损失。