CYTOSOLIC SOURCES OF NADPH AS ANTIOXIDANTS

作为抗氧化剂的 NADPH 的细胞质来源

基本信息

批准号：
7921195
负责人：
Lee McAlister-Henn
金额：
$ 8.98万
依托单位：
UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
依托单位国家：
美国
项目类别：
财政年份：
2000
资助国家：
美国
起止时间：
2000-03-01 至 2010-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7921195
关键词：
Acetates Aging-Related Process Antioxidants Area Biochemical Biological Assay Carbon Cell physiology Cells Cysteine Cytochrome c Peroxidase Cytosol DNA DNA Damage Data Degenerative Disorder Enzymes Excision Exhibits Global Change Glucosephosphate Dehydrogenase Growth Hexoses High Pressure Liquid Chromatography Hydrogen Peroxide Investigation Isocitrate Dehydrogenase Isoenzymes Kinetics Laboratories Ligand Binding Liver Longevity Mass Spectrum Analysis Measures Metabolic Metabolic Pathway Methods Mitochondria Modeling Mus NADP Nuclear Oxidants Oxidation-Reduction Oxidative Stress Pathway interactions Pattern Phenotype Physiological Proteins Relative (related person)Reporting Resistance Respiration Role Side Source Sulfhydryl Compounds System Testing Two-Dimensional Gel Electrophoresis Yeast Model System Yeasts aldehyde dehydrogenases base catalase design macromolecule mouse model mutant novel overexpression oxidation oxidative damage peroxisome prevent

项目摘要

DESCRIPTION (provided by applicant): Two cytosolic sources of NADPH, the hexose monophosphate pathway and cytosolic NADP+-specific isocitrate dehydrogenase (IDP2), have been found to be essential in preventing the accumulation of deleterious oxidative byproducts of endogenous metabolic pathways including peroxisomal beta-oxidation and mitochondrial respiration. Loss of glucose-6-phosphate dehydrogenase (ZWF1, the first enzyme in the hexose monophosphate pathway) and of IDP2 results in a rapid loss in viability of yeast cells transferred to medium with oleate or acetate as the carbon source. In contrast, loss of major cellular peroxidative enzymes has no effect on growth with these carbon sources. The lethality resulting from endogenous metabolic byproducts, and the specific requirement for cytosolic sources of NADPH to protect from this lethality, are novel observations in the area of cellular oxidative stress. Further investigation of these phenomena is proposed because oxidative damage to cellular macromolecules has been associated with numerous degenerative diseases and with the process of aging. Primary aims of this proposal include the following: (A) Proteins and DNA from strains lacking cytosolic sources of NADPH will be examined to identify specific cellular and organellar macromolecular targets of deleterious oxidants generated by normal metabolic pathways. (B) We will assess the importance of cytosolic sources and of levels of NADPH as determinants of longevity, using yeast strains lacking or overexpressing these key antioxidant enzymes for life-span analysis. (C) We will initiate biochemical analyses of mammalian IDP2, and examine the physiological relevance of co-localization of this enzyme in the cytosol and in peroxisomes using both yeast and mouse models. In addition, we will continue to examine the structural basis for the unique physiological functions of yeast IDP2. (D) Finally, we will assess global changes in pools of central metabolites and reducing equivalents to directly test fundamental hypotheses related to loss or replacement of cytosolic sources of NADPH.

描述（由申请人提供）：NADPH的两个胞质来源，单磷酸途径和胞质NADP+特异性异位酸异位酸脱氢酶（IDP2），在预防多种代谢性penagiratiration beta-oxiratiration and Ontexiratiration and coxiss beta-ofciration and coxiratiration and coxiratiration and coxiratiration and coxiir beta-oxaim coxeciration and coxiss均可累积。葡萄糖-6-磷酸脱氢酶的损失（ZWF1，单磷酸途径中的第一种酶）和IDP2的丧失导致酵母细胞以Oleate或乙酸作为碳源转移到培养基中的生存能力迅速丧失。相比之下，这些碳源的主要细胞过氧化酶的损失对生长没有影响。内源性代谢副产品产生的致死性以及NADPH胞质源以保护这种致死性的特定要求是细胞氧化应激领域的新发现。提出了对这些现象的进一步研究，因为对细胞大分子的氧化损害与多种退化性疾病以及衰老过程有关。该提案的主要目的包括以下内容：（a）缺乏NADPH胞质源的蛋白和DNA，将检查NADPH的菌株，以鉴定正常代谢途径产生的有害氧化剂的特定细胞和细胞器大分子靶标。（b）我们将使用缺乏或过表达这些关键的抗氧化剂酶进行寿命分析的酵母菌菌株来评估胞质源和NADPH水平作为寿命的决定因素。（c）我们将启动哺乳动物IDP2的生化分析，并检查使用酵母和小鼠模型在细胞质和过氧化物酶体中这种酶共定位的生理相关性。此外，我们将继续研究酵母IDP2独特生理功能的结构基础。（d）最后，我们将评估中央代谢产物池的全球变化，并减少等效物，以直接检验与NADPH的胞质源损失或替代有关的基本假设。