Nephronophthisis-related ciliopathies and ciliary specialization

项目摘要 纤毛在人类发育和健康中起着重要作用。纤毛的普遍性和多样性反映了 在由纤毛缺陷引起的多症状纤毛病中。纤毛病变基因突变的临床严重程度不同 细胞类型之间的差异，包括囊性肾病，神经和骨骼缺陷，视网膜变性， 内脏逆位和男性不育。虽然相同的基本鞭毛内运输（IFT）机制构建了所有 纤毛和鞭毛，纤毛特化的机制知之甚少。例如，纤毛 产生细胞外囊泡（EV）。EV脱落是纤毛的一般特性还是纤毛的特殊特性， 一些纤毛类型的特征是未知的。睫状体EV的功能及其对纤毛病变的贡献是 也不太了解。该项目的长期目标是确定调节纤毛的分子机制， 特化、重塑、可塑性、EV生物发生和EV功能。Cilia of the C.内唇型 2（IL 2）神经元显示几种特化：它们具有独特的微管超微结构，特化的IFT， 和电动车IL 2纤毛过渡区（TZ）和轴丝在结构上是可塑的， 在动物发育过程中，从一个典型的9+0结构到另一个非典型的6+0结构。而 纤毛和鞭毛具有9倍微管对称性，观察到微管数目的变化 在自然界中。肾初级纤毛不符合9 + 0范式。这种发育可塑性表明， 某些纤毛缺陷（纤毛病）可以在以后的时间进行矫正。我们的假设得到了最近 发现常染色体显性多囊肾病是可逆的，肾脏显示 结构塑性我们简单的C。elegans模型使我们能够揭示调节纤毛的机制， 重塑和可塑性。我们发现TZ重塑需要IFT和微管蛋白编码的组合使用， 微管蛋白同种型、谷氨酰化和微管相关蛋白。肾结石相关纤毛病 （NPHP-RC）与TZ-associated蛋白的缺陷有关。NPHP-RC包括肾单位营养不良， Meckel Gruber（MKS）、Joubert（JBTS）和Senior-Løken综合征。功能丧失的临床严重程度 NPHP-RC基因在细胞和纤毛类型之间变化，因此必须了解纤毛和EV生物学 in a variety品种of contexts上下文.我们将使用C。elegans确定机制驱动过渡区和轴丝 重塑和可塑性的非典型初级纤毛。纤毛EV脱落是一种保守的，但知之甚少 纤毛是如何以及为什么制造电动汽车的我们将测试的假设，纤毛重塑和非典型 结构影响EV生物发生和EV功能。

Project Summary Cilia play essential roles in human development and health. Ciliary ubiquity and diversity are reflected in multi-symptom ciliopathies caused by ciliary defects. The clinical severity of ciliopathy gene mutations varies between cell types and includes cystic kidney disease, neurological and skeletal defects, retinal degeneration, situs inversus, and male infertility. While the same basic intraflagellar transport (IFT) machinery constructs all cilia and flagella, the mechanisms underlying ciliary specialization are poorly understood. For example, cilia produce extracellular vesicles (EVs). Whether EV shedding is a general property of cilia or a specialized feature of some cilia types is unknown. The functions of ciliary EVs and their contributions to ciliopathies are also poorly understood. The long-term goal of this project is to identify molecular mechanisms regulating ciliary specialization, remodeling, plasticity, EV biogenesis, and EV functions. Cilia of the C. elegans inner labial-type 2 (IL2) neurons display several specializations: they have unique microtubule ultrastructure, specialized IFT, and shed EVs. The IL2 ciliary transition zone (TZ) and axoneme is structurally plastic and remodels from one structure to another during animal development: from a canonical 9+0 to non-canonical 6+0 structure. While cilia and flagella share a 9-fold microtubule doublet symmetry, variations in microtubule numbers are observed in nature. Renal primary cilia do not conform to the 9 + 0 paradigm. This developmental plasticity suggests that some ciliary defects (ciliopathies) may be corrected at later times. Our hypothesis is supported by the recent discovery that autosomal dominant polycystic kidney disease is reversible, and that the kidney displays structural plasticity. Our simple C. elegans model allows us to uncover mechanisms that regulate ciliary remodeling and plasticity. We found that TZ remodeling requires IFT and the tubulin code – combinatorial use of tubulin isotypes, glutamylation, and microtubule-associated proteins. Nephronophthisis-related ciliopathies (NPHP-RCs) are associated with defects in TZ-associated proteins. NPHP-RCs include nephronophthisis, Meckel Gruber (MKS), Joubert (JBTS), and Senior-Løken syndromes. The clinical severity of loss of function of NPHP-RC genes varies between cell and cilia types, thus it is imperative to understand ciliary and EV biology in a variety of contexts. We will use C. elegans to identify mechanisms driving transition zone and axonemal remodeling and plasticity in non-canonical primary cilia. Ciliary EV shedding is a conserved, yet little is known about how and why cilia make EVs. We will test the hypotheses that ciliary remodeling and a non-canonical structure impacts EV biogenesis and EV function.