Nutrient Sensing and Hexokinases in T. brucei

布氏锥虫的营养感应和己糖激酶

• 批准号: 8229951
• 负责人: JAMES Culvin MORRIS
• 金额: $ 36.01万
• 依托单位: CLEMSON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-01 至 2016-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8229951
• 关键词: Africa South of the Sahara; African; African Trypanosomiasis; Area; Binding; Carbon; Cell physiology; Complex; Cues; Data; Disease; Elements; Engineering; Environment; Enzymes; Gene Expression; Genes; Genetic Transcription; Glucose; Glycolysis; Goals; Growth; Human; In Vitro; Infection; Mammals; Mediating; Mission; Molecular; Monitor; Mutate; Nutrient; Outcome; Parasites; Pathway interactions; Process; Proteins; Public Health; Publishing; Regulation; Regulatory Pathway; Reporter Genes; Research; Risk; Series; Site-Directed Mutagenesis; Source; Staging; Testing; Transcript; Tropical Disease; Trypanosoma; Trypanosoma brucei brucei; Tsetse Flies; United States National Institutes of Health; Untranslated Regions; Variant; Work; base; detection of nutrient; enzyme activity; genetic element; glucose metabolism; hexokinase; in vivo; inhibitor/antagonist; neglect; response; therapeutic development

DESCRIPTION (provided by applicant): Glucose metabolism is the sole source of ATP for the infectious lifecycle stage of the African trypanosome, Trypanosoma brucei. Mis-regulation of the first enzyme in the pathway, hexokinase, is toxic to the parasite. However, little is known concerning the regulatory mechanisms that modulate expression of the two genes that encode this essential enzyme activity. The goal of this application is to identify the mechanisms the parasite employs to regulate hexokinases at the gene expression and enzyme activity levels in response to distinct environmental conditions. Preliminary data indicates the trypanosome hexokinases are dynamically regulated in response to environmental glucose levels through mechanisms that include both modulation of transcript steady-state abundance and expression, as well as changes in enzyme oligomer composition. Regulation of transcript abundance in the African trypanosome occurs primarily via post-transcriptional mechanisms as a result of information encoded in gene 3'UTRs. Elements that influence hexokinase steady-state transcript abundance will be identified by monitoring transcript levels of a reporter gene construct harboring a series of mutated hexokinase 3'UTRs. The impact of these constructs on gene expression will also be considered by scoring enzyme activity of the reporter gene. At the protein level, hexokinase hexamer composition, which the parasite can alter based on growth conditions, influences enzyme activity, including sensitivity to regulatory molecules. To understand the differences in sensitivity to regulatory molecules, site-directed mutagenesis will be used to identify domains and residues required for inhibitor binding. The impact of variants that are engineered to no longer be susceptible to regulation in vitro will be assessed in vivo by expression in T. brucei. Through the characterization of regulatory mechanisms required for hexokinase expression, new means of targeting glucose metabolism, a required parasite pathway, will be identified. PUBLIC HEALTH RELEVANCE: The proposed research is important to public health as mechanisms identified here will yield new targets for desperately needed therapeutic development for the African trypanosome while expanding our understanding of the fundamental cellular process of glucose sensing, topics that are supported by the mission of the NIH.

描述（由申请方提供）：葡萄糖代谢是非洲锥虫布氏锥虫感染生命周期阶段ATP的唯一来源。该途径中的第一种酶己糖激酶的错误调节对寄生虫是有毒的。然而，很少有人知道有关的调节机制，调节这两个基因编码这种必需的酶活性的表达。本申请的目的是确定寄生虫在基因表达和酶活性水平上调节己糖激酶以响应不同环境条件的机制。初步数据表明，锥虫己糖激酶的动态调节，以响应环境中的葡萄糖水平，通过机制，包括转录稳态丰度和表达的调制，以及在酶寡聚体组成的变化。非洲锥虫中转录本丰度的调节主要通过转录后机制发生，作为基因3'UTR中编码的信息的结果。影响己糖激酶稳态转录本丰度的元件将通过监测携带一系列突变的己糖激酶3'UTR的报告基因构建体的转录本水平来鉴定。这些构建体对基因表达的影响也将通过对报告基因的酶活性进行评分来考虑。在蛋白质水平上，寄生虫可以根据生长条件改变己糖激酶六聚体的组成，影响酶的活性，包括对调节分子的敏感性。为了理解对调节分子的敏感性的差异，将使用定点诱变来鉴定抑制剂结合所需的结构域和残基。将通过在T.布鲁塞。通过表征己糖激酶表达所需的调控机制，将确定靶向葡萄糖代谢（一种必需的寄生虫途径）的新方法。 公共卫生相关性：拟议的研究对公共卫生很重要，因为这里确定的机制将为非洲锥虫迫切需要的治疗开发产生新的目标，同时扩大我们对葡萄糖感知基本细胞过程的理解，这些主题得到NIH使命的支持。

项目成果

Quercetin, a fluorescent bioflavanoid, inhibits Trypanosoma brucei hexokinase 1.

• DOI: 10.1016/j.exppara.2010.10.011
• 发表时间: 2011-02
• 期刊: EXPERIMENTAL PARASITOLOGY
• 影响因子: 2.1
• 作者: Dodson, Heidi C.;Lyda, Todd A.;Chambers, Jeremy W.;Morris, Meredith T.;Christensen, Kenneth A.;Morris, James C.
• 通讯作者: Morris, James C.

Peptide-targeted delivery of a pH sensor for quantitative measurements of intraglycosomal pH in live Trypanosoma brucei.

• DOI: 10.1021/bi400029m
• 发表时间: 2013-05-28
• 期刊: Biochemistry
• 影响因子: 2.9
• 作者: Lin S;Morris MT;Ackroyd PC;Morris JC;Christensen KA
• 通讯作者: Christensen KA

Extra-glycosomal localisation of Trypanosoma brucei hexokinase 2.

• DOI: 10.1016/j.ijpara.2012.02.008
• 发表时间: 2012-04
• 期刊: International journal for parasitology
• 影响因子: 4
• 作者: Joice AC;Lyda TL;Sayce AC;Verplaetse E;Morris MT;Michels PA;Robinson DR;Morris JC
• 通讯作者: Morris JC

Antiparasitic lethality of sulfonamidebenzamides in kinetoplastids.

磺酰胺苯甲酰胺在动质体中的抗寄生虫致死作用。

• DOI: 10.1016/j.bmcl.2017.01.043
• 发表时间: 2017
• 期刊: Bioorganic & medicinal chemistry letters
• 影响因子: 2.7
• 作者: Hackler,Amber;Patrick,StephenL;Kahney,ElizabethW;Flaherty,DanielP;Sharlow,ElizabethR;Morris,JamesC;Golden,JenniferE
• 通讯作者: Golden,JenniferE

Characterization of an African trypanosome mutant refractory to lectin-induced death.

对凝集素诱导的死亡具有抵抗力的非洲锥虫突变体的表征。

• DOI: 10.1016/j.bbrep.2015.08.013
• 发表时间: 2015
• 期刊: Biochemistry and biophysics reports
• 影响因子: 2.7
• 作者: Hackler,AmberL;Qiu,Yijian;Patrick,StephenL;Lee,SooHee;Acosta-Serrano,Alvaro;Morris,JamesC
• 通讯作者: Morris,JamesC