New mechanisms of heterotaxy and congenital heart disease: nucleoporins at cilia

 描述（由申请人提供）：先天性心脏病是美国婴儿死亡和发病的主要原因之一。然而，我们对这种疾病的遗传原因知之甚少。为了更好地了解先天性心脏病，我们分析了心脏畸形的人类遗传学。特别是，我们研究了先天性心脏病的异位症患者的拷贝数变异。异位是一种左右模式的疾病，由于心脏成环形态发生的失败而改变心脏发育。在一个内脏异位患者中，我们发现NUP188基因重复，该基因编码一种称为核孔蛋白的核孔复合物成分。然后，我们通过敲除nup188在非洲爪蟾中模拟了这种心血管疾病，nup188概括了人类的异位表型。这项计划的主要目的是分析核孔蛋白在左右模式和先天性心脏病中的作用。我们的初步数据表明，核孔蛋白是重要的纤毛。纤毛是左右图案的关键调节器，因此纤毛的丢失可以解释左右表型。在这个提议中，我们有三个主要目标：1）分析多个核孔蛋白，看看它们是否也改变左右图案和纤毛2）使用超分辨率成像来定义纤毛底部核孔蛋白的结构和3）确定核孔蛋白有助于纤毛功能的机制。

 DESCRIPTION (provided by applicant): Congenital heart disease is one of the major causes of infant mortality and morbidity in the US. However, we know little about the genetic causes of this disease. In order to better understand congenital heart disease, we analyzed the human genetics of cardiac malformations. In particular, we studied heterotaxy patients with congenital heart disease for copy number variations. Heterotaxy is a disorder of left-right patterning and alters cardiac development due to failure of cardiac looping morphogenesis. In a heterotaxy patient, we identified duplication in the NUP188 gene, which encodes a component of the nuclear pore complex known as a nucleoporin. We then modeled this cardiovascular disease in Xenopus by knocking down nup188, which recapitulated the human heterotaxy phenotype. The main goal of this proposal is to analyze the role of nucleoporins in left-right patterning and congenital heart disease. Our preliminary data suggest that nucleoporins are important for cilia. Cilia are critical regulators of left-right patterning and so loss of cilia could explain the left-ight phenotype. In this proposal, we have three main aims: 1) Analyze multiple nucleoporins to see if they also alter left-right patterning and cilia 2) use super-resolution imaging to define the structure of nucleoporins at the base of the cilium and 3) determine the mechanism by which nucleoporins contribute to the function of cilia.