Modulation of Rab7-Dependent Degradative Pathways by Novel Adenovirus Protein

新型腺病毒蛋白对 Rab7 依赖性降解途径的调节

• 批准号: 7995957
• 负责人: CATHLEEN R CARLIN
• 金额: $ 31.54万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-12-01 至 2012-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7995957
• 关键词: Acute; Adenovirus Infections; Adenovirus Protein; Adenoviruses; Ankyrin Repeat; Antigen Presentation; Binding; Cell Polarity; Cell Surface Receptors; Cells; Cellular biology; Cholesterol; Cholesterol Homeostasis; Chronic; Chronic Obstructive Airway Disease; Complex; Cytoplasm; DNA Viruses; Data; Degradation Pathway; Disease; Disease model; Dynein ATPase; Endocytosis; Endoplasmic Reticulum; Endosomes; Ensure; Epidermal Growth Factor Receptor; Equilibrium; Evolution; Failure; Fibroblasts; Foundations; GTP Binding; Gene Expression; Gene Transduction Agent; Genes; Goals; Grant Review; Guanosine Triphosphate; Guanosine Triphosphate Phosphohydrolases; Health; Human Adenoviruses; IL8 gene; Immune response; Infection; Inflammatory; Integral Membrane Protein; Invaded; Ligands; Light; Lipids; Lung diseases; Lysosomes; Maintenance; Mediating; Membrane Protein Traffic; Microtubules; Modification; Molecular; Monomeric GTP-Binding Proteins; Motor; Normal Cell; Nuclear Pore Complex; Nuclear Translocation; Nutrient; Organelles; Pathogenesis; Pathologic Processes; Pathway interactions; Patients; Phenotype; Pneumonia; Production; Proliferating; Protein Binding; Proteins; Public Health; Receptor Down-Regulation; Receptor Protein-Tyrosine Kinases; Receptor Signaling; Recruitment Activity; Recycling; Regulation; Research; Risk Factors; Role; Sequence Homology; Signal Transduction; Sorting - Cell Movement; Spectrin; Sterols; Stress; Supraoptic Vertical Ophthalmoplegia; TNF gene; Tail; Testing; Transport Vesicles; Ubiquitin; Viral; Yeasts; base; cellular targeting; cholesterol trafficking; design; disorder risk; dynactin; endosome membrane; extracellular; human disease; insight; late endosome; loss of function; mimicry; nervous system disorder; novel; palmitoylation; pathogen; receptor; receptor expression; research study; trafficking

DESCRIPTION (provided by applicant): Endocytosis serves many important functions ranging from acquisition of extracellular nutrients to regulation of cell surface receptor expression and signal transduction, maintenance of cell polarity, and antigen presentation. Many intracellular pathogens hijack endocytic pathways in order to invade cells, proliferate, and ensure pathogen survival. Understanding the consequences of pathogenic infection has enabled greater understanding of the endocytic trafficking machinery. Isolated pathogenic genes have also been used to curb pathological processes associated with their cellular targets in human disease models. The focus of this proposal is to understand the molecular and cellular mechanisms employed by an integral membrane protein encoded by the early region 3 of human adenoviruses called RID?, which was originally identified because of its ability to divert constitutively recycling EGF receptors to lysosomes. We have recently discovered that RID? interacts with RILP and ORP1L, two known effectors for the Rab7 GTPase that governs transport from early to late endosomes and then to lysosomes. Importantly, RID? compensates for Rab7 loss-of-function, suggesting it modifies endosome membrane dynamics by coordinating recruitment of Rab7 effectors to compartments that would ordinarily be perceived as early sorting endosomes. To our knowledge this is the first protein encoded by a DNA virus that functions by Rab7 mimicry. Similar to other small GTPases, Rab7 acts by cycling between an active GTP- bound state and an inactive GDP-bound state. In contrast RID? is a non-enzymatic intrinsic membrane protein that lacks any sequence homology to Rab7, providing a remarkable example of convergent evolution. Four specific aims will test these hypotheses. 1) RID? controls microtubule-dependent vesicle transport by recruiting RILP and ORP1L which then activate minus end-directed dynein-dynactin motors. 2). RID?- RILP facilitates ESCRT-II-dependent EGF receptor sorting independent of receptor tyrosine kinase or ubiquitin status. 3) RID?-ORP1L regulates cholesterol efflux from endosomes necessary to maintain the proper lipid balance in cells. 4) RID? compensates for Rab7 loss-of-function during a productive adenovirus infection, and blunts adenovirus-induced inflammatory disease by interfering with a TNF?-EGF receptor signaling cascade that regulates IL-8 production. Altogether these studies will provide novel insights to the cell biology of membrane protein trafficking, and also the molecular basis for adenovirus-induced inflammatory disease. PUBLIC HEALTH RELEVANCE The proposed studies are relevant to public health because they will provide novel insights to the molecular pathogenesis of adenovirus pneumonia. They will generate new strategies for design of non-toxic adenovirus-based gene therapy vectors, and benefit patients with chronic obstructive pulmonary disease (COPD) and other chronic respiratory diseases where it is thought persistent adenovirus infections are an important disease risk factor. These studies will also provide the foundation for developing new treatments for patients with Niemann-Pick C disease, a progressive neurological disease that is always fatal.

描述(申请人提供)：内吞作用有许多重要的功能，从获得细胞外营养到调节细胞表面受体的表达和信号转导，维持细胞的极性，以及抗原呈递。许多细胞内病原体劫持内吞途径，以侵入细胞、增殖并确保病原体存活。了解病原性感染的后果使人们能够更好地了解内吞运输机制。在人类疾病模型中，分离的致病基因也被用来抑制与其细胞靶点相关的病理过程。这一建议的重点是了解由人腺病毒早期区域3编码的完整膜蛋白RID？所使用的分子和细胞机制，RID？最初被识别是因为它能够将结构性循环的EGF受体转移到溶酶体。我们最近才发现RID？与RILP和ORP1L相互作用，RILP和ORP1L是Rab7GTP酶的两个已知效应器，控制着从早期到晚期内切体的运输，然后再到溶酶体。重要的是，瑞德？补偿Rab7功能的丧失，这表明它通过协调Rab7效应器到通常被认为是早期分选内小体的隔室的募集来改变内吞体膜的动力学。据我们所知，这是第一个由DNA病毒编码的蛋白质，通过模仿Rab7发挥功能。与其他小的GTP酶类似，Rab7通过在活跃的GTP结合状态和不活跃的GDP结合状态之间循环来发挥作用。相比之下，RID呢？是一种非酶的固有膜蛋白，与Rab7没有任何序列同源性，提供了一个显著的收敛进化的例子。四个具体目标将检验这些假设。1)摆脱？通过招募RILP和ORP1L来控制微管依赖的囊泡运输，然后激活负端定向的动力蛋白-动力蛋白马达。2)。RID？-RILP促进ESCRT-II依赖的EGF受体分选，而不依赖于受体酪氨酸激酶或泛素状态。3)RID？-ORP1L调节维持细胞内适当的脂质平衡所必需的胆固醇从内体流出。4)摆脱？在有效性腺病毒感染期间补偿Rab7的功能丧失，并通过干扰调节IL-8产生的TNF？-EGF受体信号级联来钝化腺病毒诱导的炎症性疾病。总之，这些研究将为膜蛋白运输的细胞生物学以及腺病毒诱导的炎症性疾病的分子基础提供新的见解。公共卫生相关性拟议的研究与公共卫生相关，因为它们将为腺病毒肺炎的分子发病机制提供新的见解。他们将产生新的策略来设计无毒腺病毒为基础的基因治疗载体，并使慢性阻塞性肺疾病(COPD)和其他慢性呼吸系统疾病的患者受益，在这些疾病中，持续的腺病毒感染被认为是重要的疾病风险因素。这些研究还将为尼曼-皮克C病患者开发新的治疗方法提供基础。尼曼-皮克C病是一种进行性神经系统疾病，总是致命的。