Trypanosomatid selenophosphate synthetase structure, function and interaction with selenocysteine lyase.
Trypanosomatid selenophosphate synthetase structure, function and interaction with selenocysteine lyase.
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DOI：
10.1371/journal.pntd.0008091
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发表时间：
2020-10
影响因子：
3.8
通讯作者：
Thiemann OH
中科院分区：
文献类型：
--
作者：
da Silva MTA;Silva IRE;Faim LM;Bellini NK;Pereira ML;Lima AL;de Jesus TCL;Costa FC;Watanabe TF;Pereira HD;Valentini SR;Zanelli CF;Borges JC;Dias MVB;da Cunha JPC;Mittra B;Andrews NW;Thiemann OH
Excavata 超门的真核生物已被用作研究细胞分子过程进化的模型。引人注目的是，锥虫科人类寄生虫（T. brucei、T. cruzi 和 L. Major）保留了负责硒代半胱氨酸生物合成和掺入硒蛋白（SELENOK/SelK、SELENOT/SelT 和 SELENOTryp/SelTryp）的复杂机制，尽管这些蛋白质对于实验室控制下的寄生虫活力似乎并不是必需的条件。硒磷酸合成酶（SEPHS/SPS）在硒代谢中起着不可或缺的作用，负责催化硒磷酸的形成，硒磷酸是硒代半胱氨酸合成的生物硒供体。我们解析了 L. Major 硒磷酸合成酶的晶体结构，并证实其二聚体组织在整个生命领域具有重要的功能。我们还证明了它与硒代半胱氨酸裂解酶 (SCLY) 的相互作用，并表明它不存在于参与硒代半胱氨酸途径的其他稳定组件中，即磷酸丝氨酸-tRNASec 激酶 (PSTK)-Sec-tRNASec 合酶 (SEPSECS) 复合物和 tRNASec 特异性延伸因子 (eEFSec) 复合物。在前环布氏锥虫细胞中，硒磷酸合成酶消融后，二硫苏糖醇 (DTT) 或衣霉素的内质网应激导致生长缺陷。另一方面，只有 DTT 对表达硒磷酸合成酶 RNAi 的血流 T. brucei 产生负面影响。此外，硒蛋白 T (SELENOT) 对于两种形式的寄生虫来说都是可有可无的。总之，我们的数据表明布氏锥虫硒磷酸合成酶在调节寄生虫的内质网应激反应中发挥作用。硒既是一种有毒化合物，也是一种微量营养素。作为一种微量营养素，它参与特定蛋白质、硒蛋白（如氨基酸硒代半胱氨酸）的合成。硒代半胱氨酸的合成存在于从细菌到人类的各种生物体中。引起主要热带疾病的锥虫科原生寄生虫保留了负责硒代半胱氨酸生物合成和掺入硒蛋白的复杂机制。然而，这条途径被认为对于寄生原生生物细胞来说是可有可无的。这引起了我们的兴趣，并引发了这样的疑问：如果将其维持在细胞中，它应该处于选择压力下，因此是必要的。此外，必须发生广泛且动态的蛋白质-蛋白质相互作用，以沿着途径传递含硒中间体，以保证细胞中生物硒的有效利用。在这项研究中，我们研究了参与硒代半胱氨酸合成的不同蛋白质的分子相互作用及其在内质网氧化还原稳态中的推定参与。
Eukaryotes from the Excavata superphylum have been used as models to study the evolution of cellular molecular processes. Strikingly, human parasites of the Trypanosomatidae family (T. brucei, T. cruzi and L. major) conserve the complex machinery responsible for selenocysteine biosynthesis and incorporation in selenoproteins (SELENOK/SelK, SELENOT/SelT and SELENOTryp/SelTryp), although these proteins do not seem to be essential for parasite viability under laboratory controlled conditions. Selenophosphate synthetase (SEPHS/SPS) plays an indispensable role in selenium metabolism, being responsible for catalyzing the formation of selenophosphate, the biological selenium donor for selenocysteine synthesis. We solved the crystal structure of the L. major selenophosphate synthetase and confirmed that its dimeric organization is functionally important throughout the domains of life. We also demonstrated its interaction with selenocysteine lyase (SCLY) and showed that it is not present in other stable assemblies involved in the selenocysteine pathway, namely the phosphoseryl-tRNASec kinase (PSTK)-Sec-tRNASec synthase (SEPSECS) complex and the tRNASec-specific elongation factor (eEFSec) complex. Endoplasmic reticulum stress with dithiothreitol (DTT) or tunicamycin upon selenophosphate synthetase ablation in procyclic T. brucei cells led to a growth defect. On the other hand, only DTT presented a negative effect in bloodstream T. brucei expressing selenophosphate synthetase-RNAi. Furthermore, selenoprotein T (SELENOT) was dispensable for both forms of the parasite. Together, our data suggest a role for the T. brucei selenophosphate synthetase in the regulation of the parasite’s ER stress response. Selenium is both a toxic compound and a micronutrient. As a micronutrient, it participates in the synthesis of specific proteins, selenoproteins, as the amino acid selenocysteine. The synthesis of selenocysteine is present in organisms ranging from bacteria to humans. The protist parasites of the Trypanosomatidae family, that cause major tropical diseases, conserve the complex machinery responsible for selenocysteine biosynthesis and incorporation in selenoproteins. However, this pathway has been considered dispensable for the parasitic protist cells. This has intrigued us, and lead to question that if maintained in the cell it should be under selective pressure and therefore be necessary. Also, extensive and dynamic protein-protein interactions must happen to deliver selenium-containing intermediates along the pathway in order to warrant efficient usage of biological selenium in the cell. In this study we have investigated the molecular interactions of different proteins involved in selenocysteine synthesis and its putative involvement in the endoplasmic reticulum redox homeostasis.
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影响因子：
3.8
作者：
Abhishek K;Das S;Kumar A;Kumar A;Kumar V;Saini S;Mandal A;Verma S;Kumar M;Das P
通讯作者：
Das P
影响因子：
3.7
作者：
Collins R;Johansson AL;Karlberg T;Markova N;van den Berg S;Olesen K;Hammarström M;Flores A;Schüler H;Schiavone LH;Brzezinski P;Arnér ES;Högbom M
通讯作者：
Högbom M
DOI：
10.1107/s1744309113014632
发表时间：
2013-08-01
影响因子：
0.9
作者：
Faim, Livia Maria;Rosa e Silva, Ivan;Thiemann, Otavio Henrique
通讯作者：
Thiemann, Otavio Henrique
影响因子：
1.5
作者：
Aeby, Eric;Seidel, Viktoria;Schneider, Andre
通讯作者：
Schneider, Andre
影响因子：
4.8
作者：
Cabibbo, A;Pagani, M;Sitia, R
通讯作者：
Sitia, R