ADGRV1介导的信号通路在耳聋发生中的机制研究

ADGRV1是毛细胞听纤毛踝连接的主要组成蛋白，其基因突变引起综合征型耳聋USH2C。作为目前已知最大的G蛋白偶联受体，ADGRV1介导G蛋白信号通路的能力一直鲜有报道。申请人在前期工作中发现ADGRV1通过偶联Gαi抑制腺苷酸环化酶，从而降低胞内cAMP水平，而耳聋突变ADGRV1/Y6244fsX1调控G蛋白信号通路的能力发生异常（Hu et al., J Biol Chem 2014）。据此我们提出ADGRV1介导的信号通路在听觉中发挥重要作用，这一通路的异常可以促进耳聋发生。为验证这一假说，我们模拟上述耳聋突变构建了Adgrv1/Y6236fsX1小鼠，并将对突变小鼠的听力水平、毛细胞功能、G蛋白信号传导等进行系统研究，还将利用转录组和蛋白组学手段鉴定ADGRV1下游靶基因/靶蛋白。这一工作将帮助我们深入认识ADGRV1突变致聋的分子机制，从而为临床上诊治相关耳聋病人提供指导。

ADGRV1 is the main component of ankle links in hair cell stereocilia, and ADGRV1 mutations have been associated with syndromic hearing loss USH2C. ADGRV1 is the largest G protein-coupled receptor (GPCR), while its role in G-protein signaling transduction remained unknown for many years. Previously, we found that ADGRV1 inhibits adenine cyclase via coupling Gαi, hence reduces the intracellular level of cAMP; and that deafness-associated ADGRV1/Y6244fsX1 shows abnormal activity in this signaling pathway (Hu et al., J Biol Chem 2014). Therefore, we propose here that ADGRV1-mediated signaling pathway is important for hearing, and deficits in this pathway contributes to hearing loss. To examine this hypothesis, we established Adgrv1/Y6236fsX1 mouse line, and will systematically examine its auditory function, hair cell function, and G protein signaling transduction, et al. Furthermore, we will identify the target genes and proteins downstream of ADGRV1 using transcriptomic and proteomic techniques. This work will help us to learn more about the mechanism of ADGRV1-associated hearing loss, and provide guidance for diagnosis and treatment of deaf patients.