Opioid Peptide Synthesizing Enzymes

阿片肽合成酶

基本信息

批准号：
10163827
负责人：
IRIS LINDBERG
金额：
$ 34.5万
依托单位：
UNIVERSITY OF MARYLAND BALTIMORE
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-07-15 至 2023-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10163827
关键词：
Address Affect Binding Binding Proteins Biochemical Biological Body Weight C-terminal Cell Culture Techniques Cell model Cells Cellular biology Child Clustered Regularly Interspaced Short Palindromic Repeats Collaborations Corticotropin Defect Desire for food Development Diabetes Mellitus Disease Distress Dominant-Negative Mutation Drug Addiction Drug abuse Eating Endocrine Energy Metabolism Engineering Environment Enzymes Exhibits Genes Genetic Polymorphism Genotype Half-Life Heterozygote High Fat Diet Homeostasis Homozygote Human Human Biology Hypothalamic structure Impairment Interruption Investigation Knockout Mice Laboratories Learning LoxP-flanked allele Mediating Modeling Molecular Chaperones Molecular Conformation Mus Mutant Strains Mice Mutation Neurons Neuropeptides Obesity Opioid Opioid Peptide Pathway interactions Peptide Hydrolases Peptide Signal Sequences Peptides Phenotype Physiological Play Predisposition Pro-Opiomelanocortin Process Production Prohormone Convertase Property Proprotein Convertase 1 Proprotein Convertase 2 Protein Precursors Proteins Rewards Risk Factors Role Satiation Signal Transduction Stress Testing Tissues Variant Wild Type Mouse Work alpha-Melanocyte stimulating hormone anorexic base beta-Endorphin cost endoplasmic reticulum stress energy balance enzyme pathway feeding glucose metabolism hormonal signals in vivo inhibitor/antagonist insight lipid metabolism mouse model mutant neuronal circuitry novel obesity risk pain signal pediatric patients peptide A relating to nervous system stressor trafficking

项目摘要

The prohormone convertases PC1/3 and PC2, encoded by the genes PCSK1 and PCSK2 respectively, are the endoproteolytic enzymes responsible for the liberation of opioid-active peptides from larger precursor proteins. Prohormone convertases play important roles not only in opioid peptide-mediated pain signaling but also function in many other neuronal circuits, including in reward pathways and in hypothalamic circuits involved in feeding and energy homeostasis. For example, both rare and common variations in PCSK1 function as major risk factors for human obesity, potentially due to deficiencies in hypothalamic peptidergic processing. In collaboration with clinicians who have identified children with novel mutations in PCSK1, we have recently determined that mutant human and mouse PC1/3 proteins are subject to targeting defects which are likely to result in hypothalamic proteostatic stress. Based on our prior finding that mouse PC1/3 proteins oligomerize during synthesis, we propose that dominant-negative interactions play a major role in human PC1/3 heterozygote obesity phenotypes, affecting precursor processing to bioactive peptides involved in satiety signaling. We propose that external stressors will exacerbate even mild forms of PC1/3 conformational distress, impairing C-terminal cleavage of PC1/3 to the smaller, more active forms. These processes will ultimately converge to strongly impair precursor processing, eg. proopiomelanocortin cleavage to beta-endorphin, ACTH, and most importantly, to the anorexic peptide α- MSH. In the present proposal we will use CRISPR-engineered cell models to elucidate the cell biology and precursor processing efficacy of three human PC1/3 variants and mutants known to be strongly associated with increased risk of obesity. Secondly, we will create mouse models of two common human PCSK1 obesity mutants, and a third model of a rare but highly impaired mutant, to extend findings made in cell culture to actual secretory tissues, and to identify the specific physiologic alterations which underlie the PCSK1-mediated obesity phenotype. Lastly, we will test our hypothesis that processing deficits in proopiomelanocortin-synthesizing neurons underlie the obesity phenotype by selectively eliminating Pcsk1 expression in proopiomelanocortin-expressing cells using a floxed Pcsk1 null mouse model. The results of these studies will illuminate the biosynthetic mechanisms controlling hypothalamic peptide production that contribute to human susceptibility to a variety of diseases, from obesity to reward pathways in drug addiction.

由基因PCSK1和PCSK2编码的激素转换酶PC1/3和PC2是负责从大型前体中解放阿片类药物的内蛋白溶解酶激素转化酶不仅在阿片类肽介导的疼痛信号传导中起重要作用但也可以在许多其他神经元电路中发挥作用，包括奖励途径和下丘脑涉及进食和能量稳态的电路。例如，罕见和常见的变化 PCSK1作为人类肥胖的主要危险因素，可能是由于下丘脑不足所致肽能处理。与已经确定具有新型突变儿童的临床医生合作在PCSK1中，我们最近确定了突变的人和小鼠PC1/3蛋白受到靶向可能导致下丘脑蛋白质应激的缺陷。基于我们的先前发现小鼠PC1/3蛋白在合成过程中寡聚，我们提出了主导性的相互作用在人类PC1/3杂合子肥胖表型中起主要作用，影响前体的加工涉及饱腹感的生物活性宠物。我们建议外部压力源甚至会加剧 PC1/3构象遇险的轻度形式，PC1/3的C末端裂解损害较小，更多活动形式。这些过程最终将融合到强烈损害前体处理，例如。对β-内啡肽，ACTH，最重要的是，对厌食肽α-裂解蛋白质皮质素的裂解 MSH。在本提案中，我们将使用CRISPR工程细胞模型来阐明细胞生物学和三种人类PC1/3变体和突变体的前体处理效率已知很密切随着肥胖的风险增加。其次，我们将创建两个常见人PCSK1的鼠标模型肥胖突变体和第三个模型的罕见但高度受损的突变体，以扩展细胞中的发现向实际秘书组织进行培养，并确定基于的特定生理改变 PCSK1介导的肥胖表型。最后，我们将测试我们的假设，即处理缺陷通过选择性消除PCSK1，肥胖表型的基于肥胖表型的神经元的蛋白质素皮质素合成神经元使用Floxed PCSK1 NULL小鼠模型，在表达proopiomelanocortin的细胞中表达。结果这些研究将阐明控制下丘脑肽产生的生物合成机制从肥胖到奖励毒品的途径，这有助于人类对各种疾病的敏感性瘾。