Vesicular Transport Mechanisms in Centrosome Regulation and Ciliogenesis

中心体调节和纤毛发生中的囊泡运输机制

• 批准号: 10153833
• 负责人: Steven H Caplan
• 金额: $ 30.31万
• 依托单位: UNIVERSITY OF NEBRASKA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-05-01 至 2023-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10153833
• 关键词: Affect; Binding; Biology; Birth; Cell Cycle; Centrioles; Centrosome; Cilia; Complex; Congenital Abnormality; Data; Development; Diffusion; Disease; Distal; Docking; Endocytic Vesicle; Endosomes; Etiology; Event; Excision; Face; Family member; Fostering; Functional disorder; Future; Health; Interphase; Knowledge; Link; Malignant Neoplasms; Mammalian Cell; Mediating; Membrane; Microtubules; Mitosis; Mitotic spindle; Molecular; Mothers; Mouse Protein; Organelles; Play; Process; Proteins; Recycling; Regulation; Role; Shapes; Testing; Tubulin; Ubiquitin; Vesicle; appendage; base; beta Tubulin; ciliopathy; cilium biogenesis; gamma Tubulin; genetic regulatory protein; insight; kinetosome; novel; pericentrin; recruit; trafficking; tumorigenesis; vesicle transport

Centrosomes are microtubule nucleating and organizing organelles that directly affect the interphase microtubule array, mitotic spindles and cilia. Despite their significance in development and linkage to diseases such as cancer, ciliopathies and birth defects, fundamental aspects of centrosome function and duplication remain poorly understood. For example, some proteins within the organelle act as barriers to its duplication while others inhibit the assembly of cilia, and, thus, must be eliminated at specific points in the cell cycle to enable the step-wise progression of these events. At present, it is assumed that diffusion accounts for the exchange of most centrosomal proteins. However, trafficking of centrosomal proteins toward or away from centrosomes is a plausible but relatively unexplored mechanism for controlling centrosome duplication and ciliogenesis. Previously, we showed that the endocytic regulatory protein, EHD1, is a regulator of ciliogenesis by mediating the fusion of distal appendage vesicles on centrosomes to form the ciliary vesicle. Our data support an additional role for EHD1 in controlling the centrosome duplication cycle, by promoting the redistribution of Cep215, CP110 and pericentrin (PCNT) from centrosomes to the spindle midbody during mitosis, effectively removing these protein barriers of centrosome duplication. Our findings also implicate several EHD1-interacting partners, including the retromer and MICAL-L1. Remarkably, we now find that MICAL-L1 is anchored to the centrosome/centrioles by binding to tubulins, highlighting the possibility that it may serve as a recruiter of EHD1 to the centrosome. The objective of this application is to determine whether vesicular trafficking is a novel fundamental regulator of the centrosome duplication cycle and cilia formation. Our central hypothesis is that the EHD1/MICAL-L1/retromer recycling complex promotes a vesicular transport mechanism to strip specific regulatory proteins from centrosomes, thereby enabling key steps in centrosome duplication and ciliogenesis. Our specific aims are: 1.) Elucidate the mechanism by which endocytic vesicles remove centriolar and PCM proteins from centrosomes. We hypothesize that EHD1 (present of the cytoplasmic face of endocytic vesicles) docks with the distal appendages of centrioles, potentially via MICAL-L1, interacts with centriolar protein CP110 and PCM proteins Cep215 and PCNT, and facilitates the redistribution of these regulatory proteins to the spindle midbody as vesicular cargo. 2.) Interrogate the mechanisms by which EHD1 and its endocytic interaction partners regulate ciliogenesis. We will test the hypothesis that a EHD1/MICAL-L1/retromer complex coordinate the steps leading to ciliogenesis. Impact: Understanding the mechanisms of these processes forges a novel link between endocytic trafficking and centrosome biology, and will guide future studies to explore the etiology of centrosome dysfunction during tumorigenesis and ciliopathy.

中心体是直接影响间期的微管成核和组织细胞器 微管阵列、有丝分裂纺锤体和纤毛。尽管它们在发展和联系方面具有重要意义 癌症、纤毛病和出生缺陷等疾病、中心体功能的基本方面和 重复仍然知之甚少。例如，细胞器内的一些蛋白质充当其屏障 重复，而另一些则抑制纤毛的组装，因此必须在特定点消除 细胞周期使这些事件逐步进展。目前，假设扩散 负责大多数中心体蛋白质的交换。然而，中心体蛋白的运输 朝向或远离中心体是一种看似合理但相对未经探索的控制机制 中心体复制和纤毛发生。之前，我们表明内吞调节蛋白， EHD1，是通过介导远端附属囊泡在中心体上的融合来调节纤毛发生的 以形成睫状囊泡。我们的数据支持 EHD1 在控制中心体方面的额外作用 复制周期，通过促进 Cep215、CP110 和 Pericentrin (PCNT) 的重新分配 在有丝分裂过程中将中心体连接到纺锤体中体，有效地消除这些蛋白质屏障 中心体复制。我们的研究结果还涉及几个 EHD1 相互作用的伙伴，包括 逆转录酶和 MICAL-L1。值得注意的是，我们现在发现 MICAL-L1 锚定在中心体/中心粒上 通过与微管蛋白结合，强调了它可能作为 EHD1 招募者的可能性 中心体。本申请的目的是确定囊泡运输是否是一种新颖的 中心体复制周期和纤毛形成的基本调节因子。我们的中心假设是 EHD1/MICAL-L1/retromer 回收复合体促进囊泡运输机制剥离 来自中心体的特定调节蛋白，从而实现中心体复制和 纤毛发生。我们的具体目标是： 1.) 阐明内吞囊泡去除的机制 来自中心体的中心粒蛋白和 PCM 蛋白。我们假设 EHD1（细胞质的存在） 内吞囊泡的表面）与中心粒的远端附属物对接，可能通过 MICAL-L1， 与中心粒蛋白 CP110 和 PCM 蛋白 Cep215 和 PCNT 相互作用，并促进 这些调节蛋白作为囊泡货物重新分配到纺锤体中体。 2.) 询问 EHD1 及其内吞相互作用伙伴调节纤毛发生的机制。我们将测试 假设 EHD1/MICAL-L1/retromer 复合物协调导致纤毛发生的步骤。影响： 了解这些过程的机制在内吞运输和内吞运输之间建立了一种新的联系 中心体生物学，并将指导未来的研究，探索中心体功能障碍的病因学 肿瘤发生和纤毛病。