Unfolded Protein Response in Drosophila models of Retinitis Pigmentosa

色素性视网膜炎果蝇模型中未折叠的蛋白质反应

• 批准号: 10735578
• 负责人: HYUNG D RYOO
• 金额: $ 42.02万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-01 至 2027-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10735578
• 关键词: ATF6 gene; Acceleration; Address; Adult; Affect; Alleles; Arrestins; Binding; CCAAT-Enhancer-Binding Proteins; Cells; Complex; Coupled; Data; Dimerization; Drosophila genus; Drosophila melanogaster; Endocytosis; Endoplasmic Reticulum; Endosomes; Eye; Family; Feedback; GTP-Binding Proteins; Gene Expression; Gene Expression Profiling; Genes; Genetic; Genetic Diseases; Genetic Models; Goals; Heterodimerization; Heterozygote; Homeostasis; Homologous Gene; Human; Impairment; Laboratories; Light; Link; Mammals; Mediating; Membrane; Modeling; Mutation; Organelles; Outcome; Pathologic; Pathway interactions; Patients; Photoreceptors; Physiological; Play; Property; Proteins; Quality Control; Retina; Retinal Degeneration; Retinitis Pigmentosa; Rhodopsin; Role; Signal Induction; Signal Pathway; Signal Transduction; Site; Stress; Testing; age related; autosome; bZIP Protein; cell type; chromophore; endoplasmic reticulum stress; experimental study; fly; genomic tools; interest; misfolded protein; model organism; mutant; protein folding; proteostasis; response; sensor; trafficking; transcription factor

Project Summary Rhodopsins are G-protein coupled proteins that initiate signal transduction in response to light exposure. There is significant interest in understanding Rhodopsin homeostasis because dysfunctional Rhodopsins are among the most frequent causes of Retinitis Pigmentosa (RP), a genetic disorder with age-related retinal degeneration. Among those associated with RP are Rhodopsin mutants with impaired protein folding properties. Because Rhodopsins undergo synthesis and folding in the endoplasmic reticulum (ER), such Rhodopsin mutants could impose stress on this organelle. Those conditions activate an adaptive signaling response that regulates gene expression, widely referred to as the Unfolded Protein Response (UPR). One particular UPR signaling branch relevant to this proposal is the one mediated by the ER stress sensor PERK and its downstream effector ATF4. Among others, UPR signaling induces the expression of genes that help fold or degrade misfolded proteins in the ER, thereby affecting retinal degeneration in RP. The basic mechanisms of UPR signaling, Rh1 homeostasis, and retinal degeneration are conserved in Drosophila melanogaster. Specifically, Drosophila ninaE encodes the Rhodopsin-1 (Rh1) protein expressed in adult eye photoreceptors. A mutant allele of this gene, ninaEG69D, serves as a model for RP as it imposes ER stress, activates the UPR, and dominantly causes age-related retinal degeneration. The long-term goal of this project is to harness the genetic and genomic tools of Drosophila to understand the role of UPR in retinal degeneration. Here, I propose to investigate new UPR signaling branches that may significantly change our understanding of Rhodopsin homeostasis and retinal degeneration. In Specific Aims 1 and 2, I propose to re-evaluate the widespread idea that ATF4 is the primary downstream effector of PERK-mediated UPR. Arguing against this, we recently identified a new sub-branch of the PERK pathway mediated by Xrp1, a bZIP transcription factor. How Xrp1 is regulated and whether it affects retinal degeneration remains unclear. We will specifically test the hypothesis that Xrp1 is translationally induced by PERK. We will determine if such induction affects the course of retinal degeneration and whether Xrp1 requires heterodimerization partners to regulate some or all downstream target genes. I further propose to identify the human equivalent of the Xrp1 heterodimer complex. In Aim 3, I propose to investigate a possible link between ER stress and endosome trafficking in the RP model. Most UPR studies have focused on its role in ER homeostasis. However, our recent gene expression profiling results reveal that ninaEG69D/+ photoreceptors also induce many endosomal trafficking regulators. I propose to determine if those endosomal factors are induced by the UPR or by other unconventional signaling pathways. We will further determine if those pathways affect Rhodopsin homeostasis and the course of retinal degeneration in this RP model. A successful outcome of these plans may help significantly change our current understanding of UPR signaling pathways and retinal degeneration in RP.

项目摘要 Rhodopsin是G蛋白偶联蛋白，可响应于光暴露而启动信号转导。那里 对理解视紫红质稳态的浓厚兴趣，因为功能失调的视紫红蛋白是 视网膜炎色素炎（RP）的最常见原因，这是一种与年龄相关的视网膜变性的遗传疾病。 与RP相关的那些是蛋白质折叠特性受损的视紫红质突变体。因为 动蛋白在内质网（ER）中经历合成和折叠，这种视紫红质突变体可以 对此细胞器施加压力。这些条件激活了调节基因的自适应信号传导响应 表达，被广泛称为展开的蛋白质反应（UPR）。一个特定的UPR信号分支 与该建议相关的是由ER应力传感器PERK及其下游效应器ATF4介导的提案。 除其他外，UPR信号传导诱导了有助于折叠或降解错误折叠蛋白的基因的表达 er，从而影响RP的视网膜变性。 UPR信号传导的基本机制RH1稳态， 在果蝇中，视网膜变性是保守的。具体而言，果蝇ninae编码 在成年眼光感受器中表达的Rhodopsin-1（Rh1）蛋白。该基因的突变等位基因Ninaeg69d服务 作为RP的模型，它施加了ER应力，激活UPR并主要引起与年龄相关的视网膜 退化。该项目的长期目标是利用果蝇的遗传和基因组工具 了解UPR在视网膜变性中的作用。在这里，我建议研究新的UPR信号分支 这可能会大大改变我们对视紫红质稳态和视网膜变性的理解。具体 AIM 1和2，我建议重新评估ATF4是主要下游效应子的广泛观念 PERK介导的UPR。反对这一点，我们最近确定了一个新的PERK途径子分支 由XRP1（BZIP转录因子）介导。 XRP1的调节方式以及它是否影响视网膜变性 仍然不清楚。我们将明确检验以下假设：XRP1是由PERK转化诱导的。我们将 确定这种诱导是否影响视网膜变性的过程以及XRP1是否需要 异二聚体伴侣调节某些或所有下游靶基因。我进一步建议确定 XRP1异二聚体复合物的人类当量。在AIM 3中，我建议研究ER之间的可能联系 RP模型中的压力和内体运输。大多数UPR研究都集中在其在ER稳态中的作用。 但是，我们最近的基因表达分析结果表明，NINAEG69D/+光感受器也诱导了许多 内体贩运调节器。我建议确定这些内体因子是否由UPR诱导或 通过其他非常规信号通路。我们将进一步确定这些途径是否影响视紫红质 在此RP模型中，体内平衡和视网膜变性过程。这些计划的成功结果可能 有助于显着改变我们当前对RP中UPR信号通路和视网膜变性的理解。

项目成果

A Drosophila Reporter for the Translational Activation of ATF4 Marks Stressed Cells during Development.

• DOI: 10.1371/journal.pone.0126795
• 发表时间: 2015
• 期刊: PloS one
• 影响因子: 3.7
• 作者: Kang K;Ryoo HD;Park JE;Yoon JH;Kang MJ
• 通讯作者: Kang MJ

Drosophila as a model for unfolded protein response research.

• DOI: 10.5483/bmbrep.2015.48.8.099
• 发表时间: 2015-08
• 期刊: BMB reports
• 影响因子: 3.8
• 作者: Ryoo HD

Drosophila fabp is required for light-dependent Rhodopsin-1 clearance and photoreceptor survival.

• DOI: 10.1371/journal.pgen.1009551
• 发表时间: 2021-10
• 期刊: PLoS genetics
• 影响因子: 4.5
• 作者: Huang HW;Ryoo HD
• 通讯作者: Ryoo HD

Role of Drosophila EDEMs in the degradation of the alpha-1-antitrypsin Z variant.

• DOI: 10.3892/ijmm.2015.2109
• 发表时间: 2015-04
• 期刊: International journal of molecular medicine
• 影响因子: 5.4
• 作者: Jang BY;Ryoo HD;Son J;Choi KC;Shin DM;Kang SW;Kang MJ
• 通讯作者: Kang MJ

The GCN2-ATF4 Signaling Pathway Induces 4E-BP to Bias Translation and Boost Antimicrobial Peptide Synthesis in Response to Bacterial Infection.

GCN2-ATF4 信号通路诱导 4E-BP 进行偏向翻译并促进抗菌肽合成以应对细菌感染。

• DOI: 10.1016/j.celrep.2017.10.096
• 发表时间: 2017
• 期刊: Cell reports
• 影响因子: 8.8
• 作者: Vasudevan,Deepika;Clark,NicholasK;Sam,Jessica;Cotham,VictoriaC;Ueberheide,Beatrix;Marr2nd,MichaelT;Ryoo,HyungDon
• 通讯作者: Ryoo,HyungDon