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.

中心体是微管成核和组织的细胞器，直接影响间期 微管阵列、有丝分裂纺锤体和纤毛。尽管它们在发展中具有重要意义， 疾病，如癌症、纤毛病和出生缺陷，中心体功能的基本方面， 对重复现象的了解仍然很少。例如，细胞器中的一些蛋白质充当其屏障。 复制，而其他抑制纤毛的组装，因此，必须在特定的点消除， 细胞周期，使这些事件的逐步进展。目前，人们认为， 解释了大多数中心体蛋白的交换。然而，中心体蛋白的运输 朝向或远离中心体是一个合理的，但相对未探索的机制， 中心体复制和纤毛发生。以前，我们发现内吞调节蛋白， EHD 1是通过介导中心体上远端附属物囊泡的融合来调节纤毛发生的调节因子 形成纤毛囊泡。我们的数据支持EHD 1在控制中心体中的额外作用 复制周期，通过促进Cep 215，CP 110和pericentrin（PCNT）的重新分配， 在有丝分裂过程中，中心体到纺锤体中间体，有效地消除了这些蛋白质屏障， 中心体重复我们的研究结果还涉及几个EHD 1相互作用的伙伴，包括 retromer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， 通过与微管结合，强调了它可能作为EHD 1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的 中心体复制周期和纤毛形成的基本调节因子。我们的核心假设是 EHD 1/MICAL-L1/retromer再循环复合物促进囊泡转运机制， 从中心体的特异性调节蛋白，从而使中心体复制的关键步骤， 纤毛发生我们的具体目标是：（1）阐明内吞囊泡清除 来自中心体的中心粒和PCM蛋白。我们假设EHD 1（存在于细胞质中） 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CP 110和PCM蛋白Cep 215和PCNT相互作用，并促进 这些调节蛋白作为囊泡货物重新分布到纺锤体中间体。2.）的情况。询问 EHD 1及其内吞相互作用伴侣调节纤毛发生的机制。我们将测试 假设EHD 1/MICAL-L1/retromer复合物协调导致纤毛发生的步骤。影响力： 了解这些过程的机制，形成了一个新的联系之间的内吞运输， 中心体生物学，并将指导未来的研究，以探讨中心体功能障碍的病因， 肿瘤发生和纤毛病变。