Elucidation and Regulation of Rhodoquinone Biosynthesis in Rhodospirillum rubrum

红色红螺菌中红醌生物合成的阐明和调控

基本信息

批准号：
8035700
负责人：
Jennifer Niven Shepherd
金额：
$ 24.14万
依托单位：
GONZAGA UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-08-01 至 2015-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8035700
关键词：
Aerobic Amino Acids Aminooxyacetate Anabolism Animal Model Anthelmintics Award Bacteria Benzoquinones Bioinformatics Biological Assay Caenorhabditis elegans Candidate Disease Gene Catabolism Collaborations Data Drug Delivery Systems Drug Design Drug resistance Electron Transport Electrons Energy Metabolism Enzymes Gene Targeting Genes Genome Helminths Human In Vitro Investigation Label Laboratories Lead Length Life Lipids Livestock Mammals Metabolism Methods Methyltransferase Methyltransferase Gene Multienzyme Complexes Mutation Nematoda Nitrogen O-Demethylating Oxidoreductases Organic Chemistry Oxygen Parasites Parasitology Pathway interactions Pharmaceutical Preparations Point Mutation Preparation Process Proteins Quinones Regulation Research Personnel Resistance development Respiratory Chain Rhodospirillum rubrum Role Side Source Staging Structure Techniques Testing Toxic effect Transaminases Ubiquinone Universities Work amino group analog base cofactor design drug development drug discovery drug testing feeding gabaculine genome sequencing in vitro Assay in vivo inhibitor/antagonist mutant novel overexpression polypeptide research study rhodoquinone

项目摘要

DESCRIPTION (provided by applicant): Rhodoquinone (RQ) is an essential cofactor used in the anaerobic energy metabolism of species such as the parasitic helminths, the free-living nematode Caenorhabditis elegans (C. elegans), and the purple non-sulfur bacterium, Rhodospirillum rubrum (R. rubrum). RQ is not synthesized or used in humans and other mammals with a primarily aerobic energy metabolism. However, RQ is structurally similar to ubiquinone (coenzyme Q or Q), an important lipid component involved in the aerobic respiratory chain. Both RQ and Q have a fully substituted benzoquinone ring and a polyisoprenoid side chain of varying length (depending on species). The only difference between the structures is that RQ has an amino group (NH2) instead of a methoxy group (OCH3) on the quinone ring. Therefore, the biosynthetic pathways of RQ and Q are proposed to be similar and may diverge from common precursors. The biosynthesis of Q has been well-characterized in both eukaryotic and prokaryotic species. It has recently been shown in my laboratory that the catabolism of Q is required for RQ biosynthesis in R. rubrum. A mutant strain (F11) of R. rubrum has also been identified which can synthesize Q, but not RQ, and therefore cannot grow anaerobically. The whole genomes of the mutant F11 and its spontaneous revertant RF110 were recently sequenced. The main focus of this proposal is to identify candidate gene(s) and polypeptide(s) responsible for RQ biosynthesis using the model organism R. rubrum. Selective inhibition of a unique enzyme target used in RQ biosynthesis (e.g. an aminotransferase) may lead to highly specific antihelminthic drugs that do not have a toxic effect on the host. There are three specific aims proposed for completion within the three-year award period. Specific Aim 1 involves the characterization of the conversion of Q to RQ in R. rubrum. Both in vivo and in vitro assays will be developed to identify new RQ biosynthetic intermediates, and the source of the amino group in RQ. Inhibition assays that target RQ biosynthesis will also be performed with commercially available aminotransferase inhibitors. Specific Aim 2 focuses on characterization of the F11 mutant using complementation experiments. From sequencing data, it was determined that the F11 mutation occurs in a putative methyltransferase gene. The corresponding gene product will be overexpressed and characterized. Specific Aim 3 will take advantage of bioinformatics to identify candidate aminotransferase and O-demethylase genes involved in RQ biosynthesis in R. rubrum. Deletion mutants will be prepared from the strongest candidates to determine their role in RQ biosynthesis. Unique RQ biosynthetic enzyme targets that are identified will ultimately be used for antihelminthic drug design. PUBLIC HEALTH RELEVANCE: Rhodoquinone (RQ) is an essential aminoquinone used in the anaerobic energy metabolism of the helminth parasites and it is not found or required in mammalian hosts. Characterization of genes and gene products in the RQ biosynthetic pathway in Rhodospirillum rubrum is the focus of this proposal, and may identify a parasite-specific target for drug development.

描述（由申请人提供）：Rhodoquinone（RQ）是一种必不可少的辅助因子，用于寄生虫的厌氧能量代谢，例如寄生虫蠕虫，自由生活的线虫Caenorhabdises elegans（C. elegrans）（C. elegrans）和紫色的非硫磺非硫磺菌属，紫罗兰菌，Rhodospirillum rubrum（R.Robrum）。 RQ不合成或用于主要有氧能量代谢的人类和其他哺乳动物。但是，RQ在结构上类似于泛氨基酮（辅酶Q或Q），这是有氧呼吸链中涉及的重要脂质成分。 RQ和Q具有完全取代的苯喹酮环和不同长度的多分辨侧链（取决于物种）。结构之间的唯一区别是，RQ具有氨基氨基（NH2），而不是奎因酮环上的甲氧基组（OCH3）。因此，提议RQ和Q的生物合成途径相似，并且可能与共同前体有所不同。 Q的生物合成在真核和原核种类中都已很好地表征。最近在我的实验室中，Q的分解代谢是R. rubrum中RQ生物合成所必需的。还已经鉴定出可以合成Q而不是RQ的突变菌株（F11），因此无法厌氧生长。最近对突变体F11及其自发再生RF110的整个基因组进行了测序。该提案的主要重点是确定使用模型有机体R. rubrum来确定负责RQ生物合成的候选基因和多肽。选择性抑制RQ生物合成中使用的独特酶靶标（例如，氨基转移酶）可能会导致高度特异性的抗固定药物对宿主没有毒性作用。在三年奖励期内提出了三个具体目标。特定的目标1涉及将Q转换为R. rubrum中的RQ的表征。体内和体外测定都将开发出来，以鉴定新的RQ生物合成中间体以及RQ中氨基组的来源。靶向RQ生物合成的抑制测定也将使用市售的氨基转移酶抑制剂进行。特定目标2专注于使用互补实验的F11突变体的表征。从测序数据中，确定F11突变发生在推定的甲基转移酶基因中。相应的基因产物将过表达和表征。特定的目标3将利用生物信息学来鉴定参与R. rubrum中RQ生物合成的候选氨基转移酶和O-甲基酶基因。缺失突变体将从最强的候选者中制备，以确定其在RQ生物合成中的作用。鉴定出的独特的RQ生物合成酶靶标最终将用于抗固有药物设计。公共卫生相关性：Rhodoquinone（RQ）是用于Helminth寄生虫的厌氧能量代谢中的必不可少的氨基喹酮，在哺乳动物宿主中找不到或不需要。该提案的焦点是RQ生物合成途径中基因和基因产物的表征，它可能是该提案的重点，并且可以鉴定出用于药物开发的寄生虫特异性靶标。

项目成果

期刊论文数量（3）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Microbial eukaryotes have adapted to hypoxia by horizontal acquisitions of a gene involved in rhodoquinone biosynthesis.

DOI：
10.7554/elife.34292
发表时间：
2018-04-26
期刊：
eLife
影响因子：
7.7
作者：
Stairs CW;Eme L;Muñoz-Gómez SA;Cohen A;Dellaire G;Shepherd JN;Fawcett JP;Roger AJ
通讯作者：
Roger AJ