Molecular underpinnings of photoreceptor transcriptional regulation by CRX and NRL

CRX 和 NRL 光感受器转录调节的分子基础

• 批准号: 10562276
• 负责人: Nikolai O Artemyev
• 金额: $ 38.88万
• 依托单位: UNIVERSITY OF IOWA
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-02-01 至 2026-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10562276
• 关键词: Affinity; Binding; Biochemical; Biological Assay; Biology; CREB1 gene; CREB3 gene; CRX protein; Chromatin; Complex; Cone; DNA; DNA Binding; DNA analysis; DNA-Protein Interaction; Defect; Development; Dimerization; Disease; Elements; Exhibits; FOS gene; Gene Expression; Gene Expression Profile; Gene Expression Regulation; Genes; Genetic Transcription; Glean; Goals; Heterodimerization; Homeobox; Homeodomain Proteins; Homeostasis; Human; Individual; Inherited; Knock-out; Knowledge; Leber' s amaurosis; Length; Leucine Zippers; Link; Maintenance; Mediating; Molecular; Mutation; Mutation Analysis; Nature; Neural Retina; Outcome; Pathogenicity; Phenotype; Photoreceptors; Protein Family; Proteins; Regulation; Regulatory Element; Research; Response Elements; Retina; Retinal Cone; Retinal Degeneration; Retinal Diseases; Retinitis Pigmentosa; Rhodopsin; Rod; Signal Pathway; Site; Specific qualifier value; Specificity; Structure; Testing; Therapeutic; Tissues; Transcriptional Regulation; Vertebrate Photoreceptors; Vision Disorders; Work; attenuation; bZIP Domain; cell type; cone-rod dystrophy; defined contribution; design; disease-causing mutation; follow-up; genetic regulatory protein; homeodomain; insight; mutant; new therapeutic target; postmitotic; programs; promoter; protein protein interaction; response; retinal rods; spatiotemporal; synergism; targeted treatment; therapeutic target; transcription factor; treatment strategy

Two key transcription factors, homeodomain protein CRX and basic leucine zipper protein NRL, are at the center of gene regulation during photoreceptor differentiation and homeostasis. CRX is essential for specifying commitment of postmitotic photoreceptor precursors to the development of photoreceptor cells, whereas NRL determines the rod cell fate. In orchestrating the transcriptional program of photoreceptor development, CRX and NRL cooperate functionally and physically via a direct protein-protein interaction. Defects in photoreceptor transcriptional regulation due to mutations in the genes encoding CRX and NRL cause severe retinal diseases including retinitis pigmentosa, cone-rod dystrophy, and Leber congenital amaurosis. Despite our advanced understanding of the biology and transcriptional networks of CRX and NRL, mechanistic insight into the functions and unique synergy of these transcription factors at the atomic level is lacking. In the proposed studies, we seek to determine the crystal and solution structures of the individual DNA-bound complexes of CRX and NRL, as well as the structure of the ternary CRX/NRL/DNA complex. Although mutations in these TFs have been identified, they have not been mechanistically linked to regulation of key genes. The mechanistic predictions from the structures on how disease-causing mutations in CRX and NRL may alter DNA-binding specificity at cis-regulatory elements will be validated in the follow-up assays, including high- throughput approaches such as Spec-seq. These studies will enhance our knowledge of the functions of CRX and NRL, define the molecular nature of their synergy, and allow us to delineate specific mechanisms whereby mutant CRX and NRL proteins cause retinal diseases. We hypothesize that ultimately the structures of CRX and NRL complexed with their cis-regulatory elements will enable targeted design of therapeutics to treat visual disorders via modulation of transcriptional activities at specific promoters.

两个关键的转录因子，同源结构域蛋白CRX和碱性亮氨酸拉链蛋白NRL， 在光感受器分化和体内平衡过程中处于基因调节的中心。CRX是 对有丝分裂后感光细胞前体的发育的确定至关重要 而NRL决定视杆细胞的命运。在精心策划 在感光细胞发育的转录程序中，CRX和NRL在功能上合作， 通过蛋白质间的直接相互作用。光感受器转录缺陷 由于CRX和NRL编码基因突变引起的调节导致严重的视网膜疾病 包括色素性视网膜炎、视锥-视杆营养不良和Leber先天性黑蒙。尽管我们 深入了解CRX和NRL的生物学和转录网络， 对这些转录因子的功能和独特协同作用的机制洞察 原子水平缺乏。在所提出的研究中，我们试图确定晶体和溶液 CRX和NRL的单个DNA结合复合物的结构，以及 CRX/NRL/DNA三元复合物。虽然已经鉴定了这些TF中的突变，但它们 与关键基因的调控没有机械联系。机械预测， CRX和NRL中致病突变如何改变DNA结合的结构 顺式调节元件的特异性将在后续试验中得到验证，包括高- 通量方法，例如Spec-seq。这些研究将增进我们对 CRX和NRL的功能，定义了它们协同作用的分子本质，并使我们能够描述 突变CRX和NRL蛋白引起视网膜疾病的特定机制。我们 假设最终CRX和NRL的结构与它们的顺式调节复合， 元件将使得能够有针对性地设计治疗剂，以通过调节 在特定启动子的转录活性。