Disruption of the Putative Ribosome-Binding Motif of a Scaffold Protein Impairs Cytochrome c Oxidase Subunit Expression in Leishmania major
Disruption of the Putative Ribosome-Binding Motif of a Scaffold Protein Impairs Cytochrome c Oxidase Subunit Expression in Leishmania major
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支架蛋白假定核糖体结合基序的破坏会损害大型利什曼原虫细胞色素 c 氧化酶亚基的表达
DOI：
10.1128/msphere.00644-18
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发表时间：
2019
期刊：
影响因子：
4.8
通讯作者：
Kelly, Ben L.
中科院分区：
文献类型：
--
作者：
Cardenas, Daviel;Sylvester, Charity;Cao, Bo;Nation, Catherine S.;Pizarro, Juan C.;Lu, Hua;Guidry, Jessie;Wojcik, Edward J.;Kelly, Ben L.
在它们的寄生生命周期中，通过白蛉和脊椎动物宿主，利什曼原虫寄生虫面临着截然不同的环境，包括pH值和温度的突然变化，它们必须迅速适应这些变化。这些适应包括利什曼线虫基因表达、代谢和形态的改变，使它们能够在白蛉体内以原毛体的形式繁殖，在脊椎动物宿主体内以细胞内无尾毛体的形式繁殖。利什曼代谢适应这些变化的一个关键方面是在敌对的脊椎动物环境中维持有效的线粒体功能。这些功能，包括ATP的产生，依赖于许多线粒体蛋白的表达，包括细胞色素氧化酶（COX）亚基。值得注意的是，在哺乳动物的温度条件下，利什曼原虫主要COX亚基IV （LmCOX4）的表达和毒力依赖于flack的两个拷贝，flack是一种编码核糖体相关支架蛋白LACK（利什曼原虫RACK1同源物[活化C激酶受体]）的基因。用推测的核糖体结合基元中断变体（LACKR34D35G36→LACKD34D35E36）靶向替换内源性lack拷贝导致巨噬细胞中LmCOX4表达、线粒体适应性和复制降低的热敏寄生虫。令人惊讶的是，尽管存在这些表型，但lackd34d35e36与单体和多体相关，并且没有显示出整体蛋白质合成的主要损伤。总的来说，这些数据表明野生型（WT） LACK通过优化与核糖体的功能相互作用，协调强大的LmCOX4表达和线粒体适应度，以确保寄生虫的毒力。利什曼原虫是一种锥虫原虫，在受感染的人类宿主体内持续存在，引起一系列病理，从皮肤和粘膜表现到由多诺瓦利什曼原虫引起的内脏利什曼病。后者如果不治疗通常是致命的。L. major在哺乳动物宿主中的持续存在依赖于维持基因调控程序来支持寄生虫的基本代谢功能。其中包括线粒体all的表达和组装。主要细胞色素氧化酶（LmCOX）亚基，对利什曼病atp的产生很重要。值得注意的是，在哺乳动物条件下，LmCOX亚基的WT水平需要利什曼原虫相关支架蛋白（LACK）的阈值水平。出乎意料的是，我们发现，尽管LACK假定的核糖体结合基序的破坏不会严重扰乱核糖体结合或整体蛋白质合成，但它仍然会损害COX亚基表达、线粒体功能和毒力。我们的数据表明，在哺乳动物宿主中，LACK与利什曼原虫相互作用的质量对LmCOX亚基表达和寄生虫线粒体功能至关重要。总的来说，这些发现证实了LACK的核糖体相互作用是潜在的治疗靶点。
During their parasitic life cycle, through sandflies and vertebrate hosts, Leishmania parasites confront strikingly different environments, including abrupt changes in pH and temperature, to which they must rapidly adapt. These adaptations include alterations inLeishmaniagene expression, metabolism, and morphology, allowing them to thrive as promastigotes in the sandfly and as intracellular amastigotes in the vertebrate host. A critical aspect ofLeishmaniametabolic adaptation to these changes is maintenance of efficient mitochondrial function in the hostile vertebrate environment. Such functions, including generation of ATP, depend upon the expression of many mitochondrial proteins, including subunits of cytochromecoxidase (COX). Significantly, under mammalian temperature conditions, expression of Leishmania major COX subunit IV (LmCOX4) and virulence are dependent upon two copies ofLACK, a gene that encodes the ribosome-associated scaffold protein, LACK (Leishmaniaortholog of RACK1 [receptor for activated C kinase]). Targeted replacement of an endogenousLACKcopy with a putative ribosome-binding motif-disrupted variant (LACKR34D35G36→LACKD34D35E36) resulted in thermosensitive parasites that showed diminished LmCOX4 expression, mitochondrial fitness, and replication in macrophages. Surprisingly, despite these phenotypes, LACKD34D35E36associated with monosomes and polysomes and showed no major impairment of global protein synthesis. Collectively, these data suggest that wild-type (WT) LACK orchestrates robust LmCOX4 expression and mitochondrial fitness to ensure parasite virulence, via optimized functional interactions with the ribosome.IMPORTANCELeishmaniaparasites are trypanosomatid protozoans that persist in infected human hosts to cause a spectrum of pathologies, from cutaneous and mucocutaneous manifestations to visceral leishmaniasis caused by Leishmania donovani. The latter is usually fatal if not treated. Persistence of L. major in the mammalian host depends upon maintaining gene-regulatory programs to support essential parasite metabolic functions. These include expression and assembly of mitochondrialL. majorcytochromecoxidase (LmCOX) subunits, important forLeishmaniaATP production. Significantly, under mammalian conditions, WT levels of LmCOX subunits require threshold levels of theLeishmaniaribosome-associated scaffold protein, LACK. Unexpectedly, we find that although disruption of LACK’s putative ribosome-binding motif does not grossly perturb ribosome association or global protein synthesis, it nonetheless impairs COX subunit expression, mitochondrial function, and virulence. Our data indicate that the quality of LACK’s interaction withLeishmaniaribosomes is critical for LmCOX subunit expression and parasite mitochondrial function in the mammalian host. Collectively, these findings validate LACK’s ribosomal interactions as a potential therapeutic target.
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温度对导致利什曼原虫阶段分化的分子过程的影响。
DOI：
10.1002/j.1460-2075.1988.tb03147.x
发表时间：
1988
期刊：
The EMBO Journal
影响因子：
--
作者：
M. Shapira;J. Mcewen;C. Jaffe
通讯作者：
C. Jaffe
DOI：
10.1084/jem.20031162
发表时间：
2003-12-01
期刊：
The Journal of experimental medicine
影响因子：
--
作者：
Kelly BL;Stetson DB;Locksley RM
通讯作者：
Locksley RM
杜氏利什曼原虫前鞭毛体向无鞭毛体转化不同阶段的比较蛋白质组分析
DOI：
--
发表时间：
2001
期刊：
Medical Microbiology and Immmunology
影响因子：
--
作者：
Meike Thiel;I. Bruchhaus
通讯作者：
I. Bruchhaus
用放线菌酮处理的酿酒酵母多聚核糖体中 40S 核糖体亚基复合物的表征
影响因子：
5.3
作者：
T. Helser;Robert A. Baan;A. E. Dahlberg
通讯作者：
A. E. Dahlberg
影响因子：
10.5
作者：
ROTENBERG, MO;MORITZ, M;WOOLFORD, JL
通讯作者：
WOOLFORD, JL