Heme-, Redox-, and CO-dependent Regulation of Heme Homeostasis

血红素稳态的血红素、氧化还原和CO依赖性调节

基本信息

批准号：
10660290
负责人：
Stephen Wiley Ragsdale
金额：
$ 65.24万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-05-01 至 2027-04-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10660290
关键词：
Address Affect Affinity Antioxidants Bilirubin Biliverdine Binding Binding Sites Biological Assay Biological Availability Biological Process Carbon Monoxide Cardiac Cardiovascular Diseases Cardiovascular system Catalytic Domain Cell Cycle Cell Nucleus Central Nervous System Chemicals Chemistry Circadian Dysregulation Circadian Rhythms Co-Immunoprecipitations Complex Coupling Cytoprotection DNA Data Deuterium Diffusion Disease Distant Disulfides Environment Enzymes Exhibits Fluorescence Fluorescence Anisotropy Functional disorder Gases Genetic Transcription Goals Heat-Shock Proteins 90 Heme Hemeproteins Homeostasis Human Hydrogen Hypoxia In Vitro Inflammation Inflammatory Response Kidney Kidney Diseases Kinetics Label Length Ligation Link Lipids Liposomes Malignant Neoplasms Mammals Mass Spectrum Analysis Mediating Membrane Metabolic Diseases Metabolism Methods Mitochondria Modeling Molecular Molecular Chaperones Monitor Oxidation-Reduction Oxidative Stress Oxidative Stress Induction Oxygenases Pathology Physiological Play Process Property Proteins Regulation Reporter Research Rest Role Signal Transduction Signaling Molecule Source Sulfhydryl Compounds System Tail Transcription Repressor Travel Variant circadian pacemaker crosslink experimental study genetic corepressor heart function heme a heme oxygenase-1 heme oxygenase-2 insight meter nanodisk novel protein complex protein degradation protein function sensor transcription factor

项目摘要

Heme oxygenases (HO2 and HO2) and Rev-Erbβ play critical roles in cytoprotection and in heme-dependent CO metabolism and signaling. HO2 and Rev-Erbβ exhibit similarities in their modes of heme and thiol-disulfide redox regulation via their heme responsive motifs (HRMs). HO1 and HO2 are the sole heme degrading systems in mammals. The HOs are cytoprotective, catalyzing heme degradation to avert toxic heme buildup (>1 µM). In addition, HO produces both the cytoprotective signaling molecule CO and biliverdin (precursor of the antioxidant, bilirubin). Thus, HO1 and HO2 play a protective role against cardiovascular, renal, and central nervous system pathologies induced by heme/Fe-related oxidative stress. Rev-Erbβ, is a transcriptional repressor, exerting wide control of metabolism, inflammatory responses, and the circadian rhythm. Decreased Rev-Erb levels disrupt lipid homeostasis and cause abnormalities in heart functions like cardiac mitochondrial function, metabolism, signaling, and contractile function. HO2 binds three equivalents of heme, one at its catalytic site and another at each of its two regulatory heme responsive motifs (HRMs), whereas Rev-Erbβ binds a single heme at its HRM. HO1 binds a single heme at its catalytic core, which is highly conserved with HO2. We recently described novel roles for the HO2 catalytic core in regulating cellular heme bioavailability via heme sequestration and committing HO2 to lysosomal degradation under heme deficiency. We will now tackle how HO2 coordinates these processes for achieving cellular heme homeostasis and to determine if the inducible HO1 plays a similar sequestration role in heme bioavailability. We also uncovered novel roles for the HRMs in HO2 in shuttling heme to the catalytic site and in interacting with heme chaperones. We will now address the cellular relevance of these in vitro data and whether the chaperone transfers heme directly to the catalytic core or, as we propose, to the HRM-containing tail of HO2. Having successfully incorporated full-length-HO2 with its membrane-binding region into nanodiscs and liposomes, we will now compare the properties of this most physiologically relevant form of HO in its membrane environment with those of the soluble protein. We recently discovered that the cellular form of heme, as well as the most bioavailable form, is oxidized (in the Fe3+ state). We also identified a coupling mechanism within hemeproteins that drives conversion of their resting Fe3+ state to the Fe2+-CO state. We next intend to elucidate the cellular mechanism of Rev-Erbβ regulation starting from heme loading to carbonylation. Furthermore, we plan to reveal whether cytoprotective CO, which is generated by HO, is transferred locally and directly through a protein-protein complex formed between HO and Rev-Erb or if HO-generated CO travels to target proteins by passive cellular diffusion. Our research will help us to understand HO’s involvement in cellular protection against oxidative stress-induced cardiovascular, renal, and central nervous system pathologies and why dysfunction in Rev-erbβ is associated with disorders in metabolism, circadian rhythm, and inflammation.

血红素加氧酶（HO2 和 HO2）和 Rev-Erbβ 在细胞保护和血红素依赖性中发挥关键作用 CO 代谢和信号转导 HO2 和 Rev-Erbβ 在血红素和硫醇二硫化物模式上表现出相似性。通过血红素响应基序 (HRM) 进行氧化还原调节是唯一的血红素降解系统。在哺乳动物中，H2O 具有细胞保护作用，可催化血红素降解，以避免有毒血红素积聚 (>1 µM)。此外，H2O 还产生细胞保护信号分子 CO 和胆绿素（抗氧化剂的前体）因此，HO1 和 HO2 对心血管、肾脏和中枢神经系统具有保护作用。 Rev-Erbβ 是一种转录抑制因子，具有广泛的作用。控制新陈代谢、炎症反应和昼夜节律降低 Rev-Erb 水平会破坏脂质。体内平衡并导致心脏功能异常，如心脏线粒体功能、新陈代谢、 HO2 结合三个等价的血红素，一个在其催化位点，另一个在其催化位点。它的两个调节血红素响应基序 (HRM) 中的每一个都与它结合，而 Rev-Erbβ 在其 HRM 处结合单个血红素。 HO1 在其催化核心结合单个血红素，该血红素与 HO2 高度保守。 HO2 催化核心通过血红素隔离和承诺调节细胞血红素生物利用度的作用血红素缺乏下 HO2 到溶酶体降解我们现在将解决 HO2 如何协调这些过程。用于实现细胞血红素稳态并确定诱导型 HO1 是否发挥类似的隔离作用我们还发现了 HO2 中的 HRM 在将血红素运送到催化中的新作用。我们现在将讨论这些体外数据的细胞相关性。以及伴侣是否将血红素直接转移到催化核心，或者像我们建议的那样，转移到含有 HRM 的 HO2 的尾部已成功将全长 HO2 及其膜结合区域整合到纳米圆盘中。和脂质体，我们现在将比较这种生理上最相关的 H2O 形式在其我们最近发现血红素的细胞形式，以及生物利用度最高的形式，被氧化（Fe3+状态）。我们还确定了一种偶联机制。血红素蛋白内驱动其静息 Fe3+ 状态转变为 Fe2+-CO 状态我们接下来打算阐明从血红素负载到羰基化的 Rev-Erbβ 调节的细胞机制。此外，我们计划揭示由 H2O 产生的细胞保护性 CO 是否在局部转移并直接通过 H2O 和 Rev-Erb 之间形成的蛋白质-蛋白质复合物，或者如果 H2O 产生的 CO 移动到我们的研究将帮助我们了解 H2O2 在细胞中的参与。防止氧化应激引起的心血管、肾脏和中枢神经系统病变为什么 Rev-erbβ 功能障碍与代谢、昼夜节律和炎症紊乱有关。