Phylogenetic and syntenic data support a single horizontal transference to a Trypanosoma ancestor of a prokaryotic proline racemase implicated in parasite evasion from host defences.
Phylogenetic and syntenic data support a single horizontal transference to a Trypanosoma ancestor of a prokaryotic proline racemase implicated in parasite evasion from host defences.
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DOI：
10.1186/s13071-015-0829-y
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发表时间：
2015-04-12
影响因子：
3.2
通讯作者：
G Teixeira MM
中科院分区：
文献类型：
--
作者：
Caballero ZC;Costa-Martins AG;Ferreira RC;P Alves JM;Serrano MG;Camargo EP;Buck GA;Minoprio P;G Teixeira MM
克氏锥虫（Trypanosoma cruzi，TcPRAC）和间日锥虫（Trypanosoma vivax，TvPRAC）的脯氨酸消旋酶（Proline racemase，PRAC）参与B细胞的多克隆活化，从而导致免疫抑制和逃避宿主防御。与原核生物PRAC的相似性以及在布氏锥虫和刚果锥虫中的缺失引起了关于锥虫PRAC（TryPRAC）酶的起源、进化和功能的许多问题。我们在15种锥虫中的12种中鉴定出TryPRAC同源物为每个单倍体基因组的单拷贝基因，包括T. cruzi和T. cruzi marinkellei，T. dionisii，T. erneyi，T. rangeli，T. conorhini和T. lewisi，所有哺乳动物的寄生虫。TcPRAC基因多态性与T. cruzi基因型：TcI-TcIV和Tcbat具有独特的基因，而杂种TcV和TcVI分别含有来自亲本TcII和TcIII的TcPRACA和TcPRACB。在无尾类、蛇、鳄鱼、蜥蜴和鸟类的锥虫中鉴定出PRAC同源物。大多数锥虫具有完整的PRAC基因。T. rangeli只拥有假基因，可能正在消失。T. brucei、T. congolense及其近缘种，除了较远的相关T.间日疟原虫完全丧失了PRAC基因。TryPRAC同源物的谱系支持与锥虫发生一致的进化历史。这一发现，连同PRAC基因座的同线性，与原核PRAC的关系，通过丰富的分类群系统发育分析推断，而在其他属的锥虫、角虫和裸藻中均未发现PRAC基因，提示锥虫属的共同祖先通过单一的、古老的水平基因转移（HGT）获得了PRAC基因如前所述，来自厚壁菌门细菌，与双孢菌属和其他芽孢杆菌属物种的关系比与梭菌属的关系更密切。我们广泛的系统发育研究允许研究TryPRAC在长期和短期内的进化。TryPRAC基因分化为T. cruzi和T. rangeli，由此产生的家谱与那些使用垂直遗传基因获得的家谱一致。这里描述的TryPRAC基因的清单是理解PRAC酶在锥虫中的作用的第一步，锥虫在生命周期、毒力、感染和免疫逃避策略方面不同。本文的在线版本（doi：10.1186/s13071-015-0829-y）包含补充材料，可供授权用户使用。
Proline racemase (PRAC) enzymes of Trypanosoma cruzi (TcPRAC), the agent of Chagas disease, and Trypanosoma vivax (TvPRAC), the agent of livestock trypanosomosis, have been implicated in the B-cells polyclonal activation contributing to immunosuppression and the evasion of host defences. The similarity to prokaryotic PRAC and the absence in Trypanosoma brucei and Trypanosoma congolense have raised many questions about the origin, evolution, and functions of trypanosome PRAC (TryPRAC) enzymes. We identified TryPRAC homologs as single copy genes per haploid genome in 12 of 15 Trypanosoma species, including T. cruzi and T. cruzi marinkellei, T. dionisii, T. erneyi, T. rangeli, T. conorhini and T. lewisi, all parasites of mammals. Polymorphisms in TcPRAC genes matched T. cruzi genotypes: TcI-TcIV and Tcbat have unique genes, while the hybrids TcV and TcVI contain TcPRACA and TcPRACB from parental TcII and TcIII, respectively. PRAC homologs were identified in trypanosomes from anurans, snakes, crocodiles, lizards, and birds. Most trypanosomes have intact PRAC genes. T. rangeli possesses only pseudogenes, maybe in the process of being lost. T. brucei, T. congolense and their allied species, except the more distantly related T. vivax, have completely lost PRAC genes. The genealogy of TryPRAC homologs supports an evolutionary history congruent with the Trypanosoma phylogeny. This finding, together with the synteny of PRAC loci, the relationships with prokaryotic PRAC inferred by taxon-rich phylogenetic analysis, and the absence in trypanosomatids of any other genera or in bodonids or euglenids suggest that a common ancestor of Trypanosoma gained PRAC gene by a single and ancient horizontal gene transfer (HGT) from a Firmicutes bacterium more closely related to Gemella and other species of Bacilli than to Clostridium as previously suggested. Our broad phylogenetic study allowed investigation of TryPRAC evolution over long and short timescales. TryPRAC genes diverged to become species-specific and genotype-specific for T. cruzi and T. rangeli, with resulting genealogies congruent with those obtained using vertically inherited genes. The inventory of TryPRAC genes described here is the first step toward the understanding of the roles of PRAC enzymes in trypanosomes differing in life cycles, virulence, and infection and immune evasion strategies. The online version of this article (doi:10.1186/s13071-015-0829-y) contains supplementary material, which is available to authorized users.
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影响因子：
10.7
作者：
Castresana, J
通讯作者：
Castresana, J
影响因子：
3.7
作者：
Berneman A;Montout L;Goyard S;Chamond N;Cosson A;d'Archivio S;Gouault N;Uriac P;Blondel A;Minoprio P
通讯作者：
Minoprio P
影响因子：
2.8
作者：
Duz AL;Vieira PM;Roatt BM;Aguiar-Soares RD;Cardoso JM;Oliveira FC;Reis LE;Tafuri WL;Veloso VM;Reis AB;Carneiro CM
通讯作者：
Carneiro CM
影响因子：
3.3
作者：
Alves JM;Serrano MG;Maia da Silva F;Voegtly LJ;Matveyev AV;Teixeira MM;Camargo EP;Buck GA
通讯作者：
Buck GA
影响因子：
4
作者：
Cavazzana, Manzelio, Jr.;Marcili, Arlei;Teixeira, Marta M. G.
通讯作者：
Teixeira, Marta M. G.