Telomere end processing and telomere stability maintenance in trypanosomes
锥虫的端粒末端加工和端粒稳定性维持
基本信息
- 批准号:10503111
- 负责人:
- 金额:$ 29.7万
- 依托单位:
- 依托单位国家:美国
- 项目类别:
- 财政年份:2022
- 资助国家:美国
- 起止时间:2022-08-05 至 2026-05-31
- 项目状态:未结题
- 来源:
- 关键词:AffectAfrican TrypanosomiasisAntigenic VariationBindingBinding ProteinsBiological AssayBiologyCell ProliferationCellsChromosomesComplexDNADNA PrimaseDNA RepairDNA Repair PathwayDNA biosynthesisDNA polymerase alpha-primaseDNA-Directed DNA PolymeraseDevelopmentEXO1 geneEnsureEukaryotaEukaryotic CellEvolutionExcisionExonucleaseFamilyFutureGTP-Binding Protein alpha Subunits, GsGenerationsGenetic RecombinationGoalsHumanImmune EvasionImmune responseInfectionKnowledgeLabelLengthLigationMaintenanceMediatingNonhomologous DNA End JoiningNucleotidesOligonucleotidesOrganismParasitesPathogenesisPathway interactionsPlayPolymeraseProcessProteinsRegulationRoleStructureSurface AntigensTelomeraseTelomere MaintenanceTestingTrypanosomaTrypanosoma brucei bruceigenome integrityhomologous recombinationimprovedmutantnovelnucleaserecruittelomere
项目摘要
Project Summary
Telomere, the protein/DNA complex at the chromosome end, is essential for keeping eukaryotic cells
proliferative. Conventional DNA polymerases cannot fully replicate the linear DNA ends, and most eukaryotes
use telomerase to synthesize the telomere G-rich strand de novo. The terminal telomere G-rich 3’ overhang
(G3OH) is essential for telomerase-mediated G-strand synthesis and formation of the T-loop structure that is
critical for protection of the natural chromosome ends from illegitimate DNA processes. In addition, the length of
G3OH needs to be regulated in order to avoid excessive telomeric recombination. Generation of the telomere
G3OH involves resection of the telomere 5’ end by exonucleases after the conventional DNA replication, G-
strand synthesis by telomerase, and C-strand filled-in. In higher eukaryotes, these telomere end processes are
regulated by OB fold-containing telomere ssDNA-binding proteins, which are absent in the kinetoplastid parasite
Trypanosoma brucei. Rather, we have found that T. brucei PolIE, a telomere protein and an A family DNA
polymerase, suppresses telomerase-mediated G-strand extension, helps ensure proper telomere C-strand
synthesis, and suppresses telomeric recombination. T. brucei causes sleeping sickness in humans and regularly
switches its major surface antigen, VSG, to achieve immune evasion. VSGs are monoallelically expressed
exclusively from loci immediately upstream of the telomere. We have shown that telomere proteins not only are
essential for T. brucei cell proliferation but also regulate VSG monoallelic expression and switching. However,
other than the fact that telomerase can synthesize the telomere G-strand DNA, mechanisms of telomere end
processing and its regulation are poorly understood in T. brucei. In this project, we aim to investigate
mechanisms of T. brucei telomere end processing regulation and telomere stability maintenance. In Aim
1, we will investigate how PolIE suppresses the telomerase action and whether it also affects the ending
nucleotides of the two telomere strands. The telomere C-strand fill-in in T. brucei presumably requires a DNA
polymerase. Since PolIE is a DNA polymerase, in Aim 2.1, we will test whether its DNA polymerase domain is
critical for its role in telomere end processing regulation. We have also identified Primase-Polymerase-like
protein 2 (PPL2, with a translesion DNA synthesis activity) as a telomere protein and found that PPL2 depletion
dramatically elongates the telomere G3OH length. In Aim 2.2, we will investigate whether PPL2 is important for
telomere C-strand fill-in and whether this function is PolIE-dependent. T. brucei does not have the non-
homologous end joining (NHEJ) machinery, while dysfunctional telomeres are frequently fused through NHEJ in
higher eukaryotes. In Aim 3, we will investigate whether homologous recombination and Microhomology-
mediated end joining are major pathways for telomeric recombination in WT and PolIE-depleted cells, which will
help reveal illegitimate processes that threaten the natural chromosome ends in T. brucei. Our studies will help
us better understand the telomere protein evolution and contribute to future development of anti-parasite agents.
项目摘要
端粒是位于染色体末端的蛋白质/DNA复合物,
增殖传统的DNA聚合酶不能完全复制线性DNA末端,大多数真核生物
用端粒酶重新合成端粒富含G的链。端粒末端富含G的3'突出端
(G3 OH)对于端粒酶介导的G链合成和T环结构的形成是必需的,
对于保护天然染色体末端免受非法DNA过程的影响至关重要。此外,
G3 OH需要被调节以避免过度的端粒重组。端粒的产生
G3 OH涉及在常规DNA复制后通过核酸外切酶切除端粒5'末端,G-
通过端粒酶进行链合成,以及C-链填充。在高等真核生物中,这些端粒末端突起是
受含OB折叠的端粒ssDNA结合蛋白调节,这在动质体寄生虫中不存在
布氏锥虫相反,我们发现T.布氏杆菌PolIE、端粒蛋白和A家族DNA
聚合酶,抑制端粒酶介导的G链延伸,有助于确保适当的端粒C链
合成,并抑制端粒重组。T.布鲁氏杆菌会引起人类昏睡病,
转换其主要表面抗原VSG以实现免疫逃避。VSG单等位基因表达
仅来自紧邻端粒上游的基因座。我们已经证明,端粒蛋白不仅是
对T.布氏细胞增殖,而且还调节VSG单等位基因表达和转换。然而,在这方面,
除了端粒酶可以合成端粒G链DNA外,
对T.布鲁塞。在这个项目中,我们的目标是调查
T.布鲁氏菌端粒末端加工调控和端粒稳定性维持。在Aim中
1、研究PolIE如何抑制端粒酶活性,是否也影响端粒酶活性的终止,
两条端粒链的核苷酸。T.布氏杆菌可能需要DNA
聚合酶。由于PolIE是一种DNA聚合酶,在Aim 2.1中,我们将测试其DNA聚合酶结构域是否
其在端粒末端加工调节中的作用至关重要。我们还发现了类似引物聚合酶的
蛋白2(PPL 2,具有跨损伤DNA合成活性)作为端粒蛋白,并发现PPL 2缺失
显著延长端粒G3 OH长度。在目标2.2中,我们将研究PPL 2是否对
端粒C-链填充以及该功能是否是PolIE依赖性的。T.布鲁塞没有非-
同源末端连接(NHEJ)机制,而功能失调的端粒经常通过NHEJ融合,
高等真核生物在目标3中,我们将研究同源重组和微同源性是否-
介导的末端连接是WT和PolIE缺失细胞中端粒重组的主要途径,
有助于揭示威胁T.布鲁塞。我们的研究将有助于
我们更好地了解端粒蛋白的进化,并有助于未来的抗寄生虫药物的开发。
项目成果
期刊论文数量(0)
专著数量(0)
科研奖励数量(0)
会议论文数量(0)
专利数量(0)
数据更新时间:{{ journalArticles.updateTime }}
{{
item.title }}
{{ item.translation_title }}
- DOI:
{{ item.doi }} - 发表时间:
{{ item.publish_year }} - 期刊:
- 影响因子:{{ item.factor }}
- 作者:
{{ item.authors }} - 通讯作者:
{{ item.author }}
数据更新时间:{{ journalArticles.updateTime }}
{{ item.title }}
- 作者:
{{ item.author }}
数据更新时间:{{ monograph.updateTime }}
{{ item.title }}
- 作者:
{{ item.author }}
数据更新时间:{{ sciAawards.updateTime }}
{{ item.title }}
- 作者:
{{ item.author }}
数据更新时间:{{ conferencePapers.updateTime }}
{{ item.title }}
- 作者:
{{ item.author }}
数据更新时间:{{ patent.updateTime }}
Bibo Li其他文献
Bibo Li的其他文献
{{
item.title }}
{{ item.translation_title }}
- DOI:
{{ item.doi }} - 发表时间:
{{ item.publish_year }} - 期刊:
- 影响因子:{{ item.factor }}
- 作者:
{{ item.authors }} - 通讯作者:
{{ item.author }}
{{ truncateString('Bibo Li', 18)}}的其他基金
Mechanisms of how Trypanosoma brucei TRF maintains telomere integrity
布氏锥虫 TRF 维持端粒完整性的机制
- 批准号:
10622535 - 财政年份:2022
- 资助金额:
$ 29.7万 - 项目类别:
Mechanisms of how Trypanosoma brucei TRF maintains telomere integrity
布氏锥虫 TRF 维持端粒完整性的机制
- 批准号:
10526882 - 财政年份:2022
- 资助金额:
$ 29.7万 - 项目类别:
Telomere end processing and telomere stability maintenance in trypanosomes
锥虫的端粒末端加工和端粒稳定性维持
- 批准号:
10677878 - 财政年份:2022
- 资助金额:
$ 29.7万 - 项目类别:
Identify 70 bp repeat-associated chromatin components by End-targeting Proteomics of Isolated Chromatin segments (PICh) and initiate their functional characterization
通过分离染色质片段 (PICh) 的末端靶向蛋白质组学鉴定 70 bp 重复相关染色质成分,并启动其功能表征
- 批准号:
10417263 - 财政年份:2021
- 资助金额:
$ 29.7万 - 项目类别:
Identify 70 bp repeat-associated chromatin components by End-targeting Proteomics of Isolated Chromatin segments (PICh) and initiate their functional characterization
通过分离染色质片段 (PICh) 的末端靶向蛋白质组学鉴定 70 bp 重复相关染色质成分,并启动其功能表征
- 批准号:
10293165 - 财政年份:2021
- 资助金额:
$ 29.7万 - 项目类别:
Characterize functions of T. brucei RAP1 and TRF in antigenic variation and telom
表征 T. brucei RAP1 和 TRF 在抗原变异和端粒中的功能
- 批准号:
8603220 - 财政年份:2007
- 资助金额:
$ 29.7万 - 项目类别:
Characterize functions of T. brucei RAP1 and TRF in antigenic variation and telom
表征 T. brucei RAP1 和 TRF 在抗原变异和端粒中的功能
- 批准号:
8107285 - 财政年份:2007
- 资助金额:
$ 29.7万 - 项目类别:
相似海外基金
The catalytic core of the proteasome as a drug target to treat Human African Trypanosomiasis
蛋白酶体的催化核心作为治疗非洲人类锥虫病的药物靶点
- 批准号:
10511408 - 财政年份:2022
- 资助金额:
$ 29.7万 - 项目类别:
A One Health approach to investigating the ecology of East African trypanosomiasis in Malawian wildlife
调查马拉维野生动物中东非锥虫病生态学的“同一个健康”方法
- 批准号:
476178 - 财政年份:2022
- 资助金额:
$ 29.7万 - 项目类别:
Studentship Programs
The catalytic core of the proteasome as a drug target to treat Human African Trypanosomiasis
蛋白酶体的催化核心作为治疗非洲人类锥虫病的药物靶点
- 批准号:
10677879 - 财政年份:2022
- 资助金额:
$ 29.7万 - 项目类别:
Multi-target approach to rational design of novel therapeutics for human African trypanosomiasis
多目标方法合理设计非洲人类锥虫病新疗法
- 批准号:
10466942 - 财政年份:2021
- 资助金额:
$ 29.7万 - 项目类别:
Multi-target approach to rational design of novel therapeutics for human African trypanosomiasis
多目标方法合理设计非洲人类锥虫病新疗法
- 批准号:
10296873 - 财政年份:2021
- 资助金额:
$ 29.7万 - 项目类别:
Multi-target approach to rational design of novel therapeutics for human African trypanosomiasis
多目标方法合理设计非洲人类锥虫病新疗法
- 批准号:
10706306 - 财政年份:2021
- 资助金额:
$ 29.7万 - 项目类别:
Reducing and replacing the animal cost of functional genetics in African trypanosomiasis
减少和替代非洲锥虫病功能遗传学的动物成本
- 批准号:
NC/W001144/1 - 财政年份:2021
- 资助金额:
$ 29.7万 - 项目类别:
Research Grant
Development of new drug for African trypanosomiasis based on elucidation of the mechanism of antiprotozoal action by ribavirin.
基于利巴韦林抗原虫作用机制的阐明,开发治疗非洲锥虫病的新药。
- 批准号:
21K18230 - 财政年份:2021
- 资助金额:
$ 29.7万 - 项目类别:
Grant-in-Aid for Challenging Research (Pioneering)
Development of a novel control measure for African trypanosomiasis based on the blocking of lifecycle progression
基于生命周期进展阻断的非洲锥虫病新型控制措施的开发
- 批准号:
20K07467 - 财政年份:2020
- 资助金额:
$ 29.7万 - 项目类别:
Grant-in-Aid for Scientific Research (C)
Drug-diagnostic co-development in Tropical Medicine, combating Human African Trypanosomiasis
热带医学药物诊断联合开发,抗击非洲人类锥虫病
- 批准号:
18KK0454 - 财政年份:2019
- 资助金额:
$ 29.7万 - 项目类别:
Fund for the Promotion of Joint International Research (Fostering Joint International Research (A))