Ehrlichia Notch SLiM-activated oncoprotein inhibition of apoptosis

埃里希氏菌Notch SLiM激活的癌蛋白抑制细胞凋亡

基本信息

批准号：
10513824
负责人：
JERE W MCBRIDE
金额：
$ 40万
依托单位：
UNIVERSITY OF TEXAS MED BR GALVESTON
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-11-01 至 2026-10-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10513824
关键词：
Apoptosis Apoptosis Inhibitor Apoptotic BCL-2 Protein BIR Domain Bacteria Binding CASP3 gene Caspase Cell Communication Cell Survival Cell physiology Cells Development Disease Down-Regulation Ehrlichia Ehrlichia chaffeensis Ehrlichiosis Etiology Eukaryotic Cell Event FBXW7 gene Genetic Transcription Genome Goals Host Defense Host Defense Mechanism Human Immune Immune Evasion Infection Inflammation Inhibition of Apoptosis Investigation Knowledge Laboratories Life Ligands Link MCL1 gene Mediating Membrane Proteins Mitochondria Molecular Molecular Mimicry Mononuclear Notch Signaling Pathway Oncoproteins Pathway interactions Phagocytes Play Positioning Attribute Post-Translational Protein Processing Protein Inhibition Proteins Receptor Signaling Regulation Research Role Science Signal Pathway Signal Transduction Surface System TLR2 gene Tandem Repeat Sequences Toll-like receptors in vivo mimetics mimicry new therapeutic target notch protein novel therapeutic intervention pathogen prevent programs protein protein interaction receptor receptor binding receptor expression tick-borne ubiquitin ligase

项目摘要

ABSTRACT Ehrlichia chaffeensis (E. ch.) is a gram-negative, obligately intracellular bacterium and the etiologic agent of human monocytotropic ehrlichiosis (HME), an emerging, life-threatening, tick-borne zoonosis. E. ch. preferentially infects mononuclear phagocytes and survives intracellularly by subverting innate immune defenses mediated in part by tandem repeat protein (TRP) effectors. Within the last decade, our laboratory has identified a multitude of molecular ehrlichial TRP-host interactions, many that are new to science, illuminating the breath and complexity of pathogen-host interaction dynamics that occur during infection. We have shown that E. ch. is dependent on activation of conserved eukaryotic signaling pathways including Notch and Wnt for infection. However, understanding the molecular basis of Notch activation events, whereby E. ch. repurposes Notch signaling for infection remains a major gap in our knowledge. Thus, the purpose of this investigation is to define the molecular and cellular mechanisms E. ch. has evolved to repurpose Notch signaling for infection. We propose that E. ch. TRP120 has distinct eukaryotic protein interaction modules known as short linear motifs (SLiMs) that mimic Notch ligand function and directly engage cognate receptors to exploit Notch signaling for infection. This investigation will address our limited understanding of the functionally diverse roles of protein interaction modules in the continuum of host-pathogen interactions and cellular reprogramming. The long-term goal of this research is to define the molecular basis of Ehrlichia host cell mimicry, and the mechanisms involved in infection and immune evasion. The objective of this proposal is to determine the molecular interactions involved and functional mechanisms whereby E. ch. TRP120 Notch ligand mimicry establishes and promotes infection by inhibiting host cell apoptosis. We hypothesize that E. ch. TRP120 has a Notch SLiM mimetic that activates Notch signaling to upregulate anti-apoptotic regulators (MCL1 and NICD), thereby inhibiting mitochondrial apoptotic signaling and caspase activation. Aim 1 will define the E. ch. TRP120 Notch SLiM mimetic and investigate receptor binding and signaling; Aim 2 will examine E. ch. TRP120 Notch-upregulated MCL1 inhibition of mitochondrial apoptosis; and Aim 3 will investigate the role of E. ch. Notch stabilization of XIAP and inhibition of caspase activation. This investigation will extend our knowledge of the molecular interactions by which E. ch. TRP120 surface protein exploits Notch signaling to inhibit apoptosis and promote host cell survival and infection. The significance of this research is defining the mechanistic strategies whereby intracellular pathogens with small genomes and a limited number of effector proteins, have evolved host mimicry modules to repurpose host cell signaling to manipulate downstream host defense mechanisms for infection. A molecular understanding of E. ch. pathobiology will also facilitate development of novel therapeutic approaches for Ehrlichia spp. and intracellular pathogens that utilize SLiM mimicry or exploit conserved cellular pathways for infection and immune evasion.

抽象的 ehrlichia chaffeensis（E。Ch。）是一种革兰氏阴性菌，有规律的细胞内细菌，是一种病因人类单核细胞性ehrlichiisois（HME），一种新兴的，威胁生命的，tick虫的人畜共患病。 E. ch。优先感染单核吞噬细胞并通过颠覆先天免疫防御能力在细胞内生存部分由串联重复蛋白（TRP）效应子介导。在过去的十年中，我们的实验室已经确定许多分子ehrlichial trp-host互动，许多是科学的新手，亮着呼吸感染过程中发生的病原体宿主相互作用动力学的复杂性。我们已经证明了E. ch。是取决于保守的真核信号通路的激活，包括缺口和Wnt用于感染。但是，了解Notch激活事件的分子基础，从而使E. Ch。重新利用缺口感染的信号传导仍然是我们所知的主要差距。因此，这项调查的目的是定义分子和细胞机制E. ch。已演变为重新利用档位信号传导以进行感染。我们建议那个E. ch。 TRP120具有不同的真核蛋白相互作用模块，称为短线性基序（Slim）模仿Notch配体功能，并直接吸收相关受体以利用Notch信号传导进行感染。这调查将解决我们对蛋白质相互作用模块功能多样性作用的有限理解在宿主 - 病原体相互作用和细胞重编程的连续性中。这项研究的长期目标是定义ehrlichia宿主细胞模仿的分子基础，以及涉及感染和的机制免疫逃避。该建议的目的是确定所涉及的分子相互作用和功能 E. ch。 TRP120 Notch配体模仿通过抑制宿主建立并促进感染细胞凋亡。我们假设E. ch。 TRP120具有一个缺口纤细的模拟物，可以激活Notch信号传导上调抗凋亡调节剂（MCL1和NICD），从而抑制线粒体凋亡信号传导和 caspase激活。 AIM 1将定义E. ch。 TRP120 Notch Slim Mimetic并研究受体结合和信号传导； AIM 2将检查E. ch。 TRP120 Notch升级的MCL1抑制线粒体凋亡； AIM 3将研究E. ch的作用。 XIAP的缺口稳定和caspase激活的抑制作用。这研究将扩展我们对E. ch的分子相互作用的了解。 TRP120表面蛋白利用Notch信号传导抑制凋亡并促进宿主细胞的存活和感染。这一点的意义研究正在定义机械策略，从而使用小基因组和有限的细胞内病原体效应蛋白的数量，已经发展为宿主模拟模块以重新利用宿主细胞信号传导以操纵下游宿主防御机制用于感染。对E. ch的分子理解。病理生物学也将有助于开发用于Ehrlichia spp的新型治疗方法。和利用的细胞内病原体纤细的模仿或开发保守的细胞途径，以进行感染和免疫逃避。