ER-aminopeptidases: Conformational regulation and antigen presentation function

ER-氨基肽酶：构象调节和抗原呈递功能

• 批准号: 10664968
• 负责人: Lawrence J. Stern
• 金额: $ 50.25万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-07 至 2024-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10664968
• 关键词: Active Sites; Affect; Aminopeptidase; Ankylosing spondylitis; Antigen Presentation; Autoimmune Diseases; Autoimmunity; Behavior; Behcet Syndrome; Binding; Binding Proteins; Biochemical; Catalysis; Cellular Assay; Chromosome 5; Complex; Couples; Cross Presentation; Cryoelectron Microscopy; Data; Dependence; Development; Disease; Distal; ERAP1 gene; Endoplasmic Reticulum; Endosomes; Enzymatic Biochemistry; Enzymes; Epitopes; Equilibrium; Essential Hypertension; Family; Family member; Gene Cluster; Genes; Genetic Polymorphism; Human; Human Chromosomes; Hypertension; Immune response; Infectious Agent; Inflammation; Interferon Type II; Length; Malignant Neoplasms; Mediating; Modeling; Molecular Chaperones; Molecular Conformation; Motion; Mutation; Nature; Peptides; Population; Positioning Attribute; Pre-Eclampsia; Predisposition; Proteins; Psoriasis; Regulation; Research; Retinal Diseases; Risk; Role; Shapes; Sodium Chloride; Solvents; Specificity; Structure; Testing; Variant; Virus; Work; Zinc; antigen processing; conformational alteration; conformer; endoplasmic reticulum stress; enzyme activity; genetic association; genetic variant; in vivo; inhibitor; insight; member; paralogous gene; small molecule inhibitor; tapasin; therapeutic development; tool; tumor

PROJECT SUMMARY/ABSTRACT ERAP1, ERAP2, and IRAP are M1-family zinc aminopeptidases with important roles in trimming antigenic peptide precursors for loading onto MHC-I proteins. Common polymorphisms in the erap1 gene are associated with increased susceptibility to autoimmune diseases including ankylosing spondylitis, psoriasis, Behçet's disease, and birdshot retinopathy, increased susceptibility to certain kinds of cancer, and essential hypertension. Polymorphic residues are located distal to the enzyme active site, and the mechanism underlying their effects on enzymatic activity is unknown. ERAP2 polymorphisms are less common and more weakly associated with autoimmune diseases than for ERAP1. Key questions about ER aminopeptidases include their mechanism of action, in particular the mechanistic basis for the unique length-dependent cleavage activity, the nature of the linkage of polymorphic variants with autoimmune disease, and to what degree mechanistic insights about ERAP1 can be extended to the other members of the oxytocinase subfamily ERAP2 and IRAP. An overarching hypothesis of this proposal is that large-scale conformational alterations provide a mechanistic underpinning for the effects of ER aminopeptidase polymorphisms on enzymatic activity and disease association, and that the conformational equilibria are modulated by interactions with other proteins in the endoplasmic reticulum. One specific aim of the proposed research is to understand how interactions between ER aminopeptidase domains regulate enzyme activity. A detailed mechanistic model for ERAP1 catalytic mechanism will be developed and tested. The model couples ERAP1 binding interactions near the N- and C-termini of peptide substrates with large-scale domain closure motions that stabilize the catalytically active configuration of key active site residues. Using salt-bridge mutations known to alter ERAP1 conformational dynamics, and small-molecule inhibitors that alter ERAP1 conformational equilibria, we will test whether disease-associated polymorphisms act through differential stabilization of open and closed conformers, and we will determine whether ERAP2 and IRAP similarly utilize large-scale domain closure motions to regulate enzymatic activity. A second specific aim is to determine the structural basis and functional consequences of ERp44-mediated endoplasmic reticulum retention of ERAP1 and ERAP2. We aim to determine structures of complexes of ERp44 with ERAP1 and ERAP2, to characterize the effect of ERp44 interaction on ERAP1 and ERAP2 processing, and to evaluate the role of ERAP1-ERp44 interactions in generating new epitopes under ER stress. A third specific aim is to evaluate the influence of the ER chaperones tapsin and TAPBPR on ERAP1 trimming of epitope precursors while they are bound to MHC-I. 1

项目摘要/摘要 ERAP1，ERAP2和IRAP是M1家族锌非肽酶，在修剪抗原方面重要作用 用于加载到MHC-I蛋白上的肽前体。 ERAP1基因中的常见多态性是相关的 随着对自身免疫性疾病的易感性增加，包括高甲虫炎，牛皮癣，贝sket的易感性 疾病和鸟类视网膜病，增加了对某些类型癌症的敏感性和基本高血压。 多态残差位于酶活性位点的远端，其作用的基础机制 酶促活性尚不清楚。 ERAP2多态性不那么普遍，与 自身免疫性疾病比ERAP1。有关ER障碍酶的关键问题包括它们的机制 作用，特别是独特的长度依赖性切割活动的机械基础， 多态性变体与自身免疫性疾病的联系，以及有关ERAP1的机械性见解 可以扩展到催产酶亚家族ERAP2和IRAP的其他成员。总体 该提议的假设是，大规模构象改变为基础提供了机械基础 ER障碍酶多态性对酶活性和疾病关联的影响，以及 构象等效因素与内质网中其他蛋白质的相互作用调节。一 拟议的研究的具体目的是了解ER无肽酶域之间的相互作用 调节酶活性。将开发出一个ERAP1催化机制的详细机械模型，并 测试。该模型伴侣ERAP1结合相互作用在胡椒底物的N和C末端与 稳定关键活性位点催化活性构型的大型域闭合运动保留。 使用已知改变ERAP1构象动力学的盐桥突变，以及小分子抑制剂 改变ERAP1构象平衡，我们将测试与疾病相关的多态性是否通过 开放和封闭构象体的差异稳定，我们将确定ERAP2和IRAP是否 同样，利用大规模的结构域闭合运动来调节酶活性。第二个具体目标是 确定ERP44介导的内质网的结构基础和功能后果 ERAP1和ERAP2。我们旨在确定ERP44与ERAP1和ERAP2的复合物的结构， 表征ERP44相互作用对ERAP1和ERAP2处理的影响，并评估 ERAP1-ERP44相互作用在产生新的表位下的ER应力下。第三个具体目的是评估 ER伴侣Tapsin和tapbpr的影响对ERAP1的表位前体的修剪时的影响 绑定到MHC-I。 1

项目成果

Conformational dynamics linked to domain closure and substrate binding explain the ERAP1 allosteric regulation mechanism.

• DOI: 10.1038/s41467-021-25564-w
• 发表时间: 2021-09-06
• 期刊: Nature communications
• 影响因子: 16.6
• 作者: Maben Z;Arya R;Georgiadis D;Stratikos E;Stern LJ
• 通讯作者: Stern LJ

Phenylsulfamoyl Benzoic Acid Inhibitor of ERAP2 with a Novel Mode of Inhibition.

具有新型抑制模式的 ERAP2 苯基氨磺酰苯甲酸抑制剂。

• DOI: 10.1021/acschembio.2c00093
• 发表时间: 2022
• 期刊: ACS chemical biology
• 影响因子: 4
• 作者: Arya,Richa;Maben,Zachary;Rane,Digamber;Ali,Akbar;Stern,LawrenceJ
• 通讯作者: Stern,LawrenceJ