Non-linear hierarchy of the quorum sensing signalling pathway in bloodstream form African trypanosomes.
Non-linear hierarchy of the quorum sensing signalling pathway in bloodstream form African trypanosomes.
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DOI：
10.1371/journal.ppat.1007145
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发表时间：
2018-06
期刊：
影响因子：
6.7
通讯作者：
Matthews KR
中科院分区：
文献类型：
--
作者：
McDonald L;Cayla M;Ivens A;Mony BM;MacGregor P;Silvester E;McWilliam K;Matthews KR
布氏锥虫是非洲锥虫病的病原体，在哺乳动物血液中会发生密度依赖性分化，为通过采采蝇传播做准备。这涉及从增殖的细长型产生细胞周期停滞的、静止的、短粗型。利用全基因组选择性筛选，已对负责群体感应反应的信号通路进行了分类，提供了信号蛋白激酶、磷酸酶、RNA结合蛋白和假定蛋白的概要。然而，这些成分的顺序尚不清楚。为了将这些成分拼凑在一起，以描述短粗型是如何形成的，我们采用了一种基因外抑制方法。这种方法利用组合基因敲除和过表达策略，来评估通路成分的无效突变体中发育能力的丧失是否可通过其他成分的异位表达来补偿。我们已经为短粗诱导因子信号通路中的三个基因（RBP7、YAK、MEKK1）创建了无效突变体，并通过表达RBP7、NEK17、PP1 - 6或对假定的分化抑制剂TbTOR4进行诱导性基因沉默来评估互补情况。这表明该信号通路是非线性的。以一种通路成分（一种假定的MEKK）为重点的磷酸蛋白质组分析，确定了在MEKK1无效突变体中表达和磷酸化谱发生改变的分子，包括通路中的另一个成分NEK17。我们的数据首次对锥虫中一个信号转导级联的多个成分进行了分子剖析。
非洲锥虫寄生虫对其哺乳动物宿主血液中的密度感应信息作出反应，以产生其传播阶段——短粗型。这种“群体感应”信号级联的成分是已知的，但它们的相互作用和顺序未知。在这里，我们通过组合基因敲除和异位表达，以及对一个成分进行详细的磷酸蛋白质组分析，剖析了通路中分子之间的依赖关系。我们的结果首次对信号通路结构进行了分析，揭示其是非线性的。此外，磷酸蛋白质组分析通过确定当一种预测的上游激酶缺失时，通路中一种NEK激酶成分的磷酸化降低，揭示了通路的层级结构。这为对这些利用群体感应控制疾病传播的寄生虫的信号转导级联进行连贯剖析提供了一个框架。
Trypanosoma brucei, the agents of African trypanosomiasis, undergo density-dependent differentiation in the mammalian bloodstream to prepare for transmission by tsetse flies. This involves the generation of cell-cycle arrested, quiescent, stumpy forms from proliferative slender forms. The signalling pathway responsible for the quorum sensing response has been catalogued using a genome-wide selective screen, providing a compendium of signalling protein kinases phosphatases, RNA binding proteins and hypothetical proteins. However, the ordering of these components is unknown. To piece together these components to provide a description of how stumpy formation arises we have used an extragenic suppression approach. This exploited a combinatorial gene knockout and overexpression strategy to assess whether the loss of developmental competence in null mutants of pathway components could be compensated by ectopic expression of other components. We have created null mutants for three genes in the stumpy induction factor signalling pathway (RBP7, YAK, MEKK1) and evaluated complementation by expression of RBP7, NEK17, PP1-6, or inducible gene silencing of the proposed differentiation inhibitor TbTOR4. This indicated that the signalling pathway is non-linear. Phosphoproteomic analysis focused on one pathway component, a putative MEKK, identified molecules with altered expression and phosphorylation profiles in MEKK1 null mutants, including another component in the pathway, NEK17. Our data provide a first molecular dissection of multiple components in a signal transduction cascade in trypanosomes. African trypanosome parasites respond to density sensing information in the bloodstream of their mammalian hosts to generate their transmission stage, the stumpy form. Components of this ‘quorum sensing’ signalling cascade are known but their interactions and ordering are not. Here we have dissected the dependency relationships between molecules in the pathway by combinatorial gene knockout and ectopic expression, as well as by detailed phosphoproteomic analysis of one component. Our results provide a first analysis of the signal pathway architecture, revealing that it is non-linear. Moreover, phosphoproteome analysis reveals pathway hierarchy through identifying that the phosphorylation of a NEK kinase component of the pathway is reduced when a predicted upstream kinase is absent. This provides a framework for the coherent dissection of a signal transduction cascade in these parasites that use quorum sensing to control disease spread.
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影响因子：
4.4
作者：
Brenchley R;Tariq H;McElhinney H;Szöor B;Huxley-Jones J;Stevens R;Matthews K;Tabernero L
通讯作者：
Tabernero L
影响因子：
1.5
作者：
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影响因子：
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作者：
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通讯作者：
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影响因子：
1.5
作者：
Gallet, Cecile;Demonchy, Raphael;Kohl, Linda
通讯作者：
Kohl, Linda
影响因子：
30.3
作者：
Guttery DS;Poulin B;Ramaprasad A;Wall RJ;Ferguson DJ;Brady D;Patzewitz EM;Whipple S;Straschil U;Wright MH;Mohamed AM;Radhakrishnan A;Arold ST;Tate EW;Holder AA;Wickstead B;Pain A;Tewari R
通讯作者：
Tewari R