Intercellular Signaling and Endosome to Golgi Transport in Multicellular Animals

多细胞动物的细胞间信号传导和内体到高尔基体的运输

• 批准号: 8608558
• 负责人: Barth Demian Grant
• 金额: $ 29.45万
• 依托单位: RUTGERS, THE STATE UNIV OF N.J.
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-02-01 至 2017-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8608558
• 关键词: AMPA Receptors; Actins; Alzheimer' s Disease; Animals; Apoptotic; Binding; Caenorhabditis elegans; Cell membrane; Cell physiology; Cells; Centers for Disease Control and Prevention (U.S.); Clathrin; Collaborations; Complex; Copper; Data; Development; Disease; Drosophila genus; Endosomes; Epithelial; Event; Feedback; Generations; Genetic Screening; Goals; Golgi Apparatus; Guanosine Triphosphate Phosphohydrolases; Health; Human; IGF Type 2 Receptor; Immunity; Ligands; Link; Lysosomal Storage Diseases; Lysosomes; Malignant Neoplasms; Mammalian Cell; Mediating; Membrane; Menkes Kinky Hair Syndrome; Metabolism; Microscopic; Molecular; Molecular Chaperones; Nematoda; Nervous system structure; Organism; PARD6A gene; Parkinson Disease; Pathogenicity; Pathway interactions; Phylogenetic Analysis; Process; Proteins; RNA Interference; Receptor Signaling; Recycling; Regulation; Research; Retrieval; Ricin; Role; SH3 Domains; Signal Pathway; Signal Transduction; Sorting - Cell Movement; System; Tertiary Protein Structure; Testing; Toxin; Transducers; WAVE protein; Work; Yeasts; combat; disorder control; genetic regulatory protein; genome-wide; improved; insight; intestinal epithelium; mutant; novel; protein complex; protein function; public health relevance; receptor; retrograde transport; therapeutic target; trafficking

DESCRIPTION (provided by applicant): Our long-term goal in this proposal is to identify and understand the cellular components that transport internalized endocytic cargo from endosomes to the Golgi apparatus (retrograde recycling), and to understand how this process regulates, and is integrated within, intercellular signaling pathways. Retrograde recycling has recently been linked to multiple metazoan-specific processes such as the generation of Wnt signaling gradients, AMPA-receptor signaling in the nervous system, clearance of dead apoptotic cells, and regulation of epithelial polarity. Wnt signaling requires endosome-to-Golgi retrieval of the Wnt ligand chaperone MIG-14/Wntless, and the molecular details of MIG-14/Wntless recycling have proven to be highly conserved in C. elegans, Drosophila, and mammalian cells. Without retrograde recycling, transmembrane cargo proteins such as MIG-14/Wntless aberrantly enter the lysosome and are degraded, thus depleting the functional pool of such proteins from the cell. To gain novel insight into how retrograde recycling functions, and how it influences intercellular signaling mechanisms in multicellular animals, we have pioneered analysis of the polarized intestinal epithelium of C. elegans. In novel preliminary work we discovered that TGF?-signaling is impaired in retrograde recycling mutants. We plan to further test the hypothesis that TGF?-receptors are retrograde cargo, and test phylogenetic conservation of this mechanism in Drosophila and mammalian cells. In addition, our team has discovered previously unsuspected requirements for endosome regulatory proteins beyond the well-studied retromer complex. These novel regulators include the J-domain co-chaperone RME-8. We plan to test the hypothesis that RME-8 regulates the disassembly of the endosomal flat clathrin lattice, mediating a feedback loop between retromer and the ESCRT-driven degradation machinery that is present on the same endosomes. In addition we have identified an entire additional protein complex involved in retrograde recycling of MIG-14/Wntless. This protein complex appears to be associated with the recycling endosome, and contains modules for membrane binding, membrane bending, and actin nucleation. We plan to determine how this protein complex influences MIG-14/Wntless recycling, test its ability to influence other retrograde cargo including TGF?-receptors, and test for conservation of function in mammalian cells. We expect that our findings will provide unique insight into how trafficking mechanisms influence signaling pathways, and will improve our ability to treat diverse diseases that arise from misregulation of receptor signaling strength, such as in cancers, and other diseases associated with misregulated retrograde recycling including Alzheimer's and Parkinson's diseases.

描述（由申请人提供）：我们在本提案中的长期目标是识别和理解将内吞货物从内体运输到高尔基体（逆行回收）的细胞成分，并了解该过程如何调节并整合到细胞间信号通路中。最近，逆行回收与多种后生动物特异性过程相关，例如 Wnt 信号梯度的产生、神经系统中的 AMPA 受体信号传导、死亡凋亡细胞的清除以及上皮极性的调节。 Wnt 信号传导需要从内体到高尔基体修复 Wnt 配体伴侣 MIG-14/Wntless，并且 MIG-14/Wntless 回收的分子细节已被证明在秀丽隐杆线虫、果蝇和哺乳动物细胞中高度保守。如果没有逆行回收，跨膜货物蛋白（例如 MIG-14/Wntless）会异常进入溶酶体并被降解，从而耗尽细胞中此类蛋白的功能库。为了深入了解逆行回收功能及其如何影响多细胞动物的细胞间信号传导机制，我们率先对秀丽隐杆线虫的极化肠上皮进行了分析。在新的初步工作中，我们发现逆行回收突变体中 TGFβ 信号传导受损。我们计划进一步测试TGFβ受体是逆行货物的假设，并测试果蝇和哺乳动物细胞中这一机制的系统发育保守性。此外，我们的团队还发现了除了经过充分研究的逆转录体复合物之外对内体调节蛋白的先前未曾怀疑的需求。这些新型调节因子包括 J 域辅助伴侣 RME-8。我们计划测试这样的假设：RME-8 调节内体扁平网格蛋白晶格的分解，介导逆转录体和存在于同一内体上的 ESCRT 驱动的降解机制之间的反馈回路。此外，我们还发现了参与 MIG-14/Wntless 逆行回收的完整额外蛋白质复合物。这种蛋白质复合物似乎与循环内体相关，并包含膜结合、膜弯曲和肌动蛋白成核的模块。我们计划确定这种蛋白质复合物如何影响 MIG-14/Wntless 回收，测试其影响其他逆行货物（包括 TGFβ-受体）的能力，并测试哺乳动物细胞中的功能保守性。我们期望我们的研究结果将为贩运机制如何影响信号通路提供独特的见解，并将提高我们治疗因受体信号强度失调而引起的多种疾病的能力，例如癌症，以及与逆行再循环失调相关的其他疾病，包括阿尔茨海默病和帕金森病。