Prophenoloxidase activation is required for survival to microbial infections in Drosophila.
Prophenoloxidase activation is required for survival to microbial infections in Drosophila.
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DOI：
10.1371/journal.ppat.1004067
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发表时间：
2014-05
期刊：
影响因子：
6.7
通讯作者：
Lemaitre B
中科院分区：
文献类型：
--
作者：
Binggeli O;Neyen C;Poidevin M;Lemaitre B
黑化反应是节肢动物的一种主要免疫反应，涉及感染和损伤部位黑色素的快速合成。在黑化过程中的一个关键酶是酚氧化酶(PO)，它催化苯酚氧化成苯二酚，然后聚合成黑色素。果蝇基因组编码三种POS，主要以酶原或酚氧化酶(PPO)的形式产生。其中两种是由晶体细胞产生的PPO1和PPOO2。在这里，我们产生了携带PPO1和PPO2缺失的苍蝇。通过单独和联合分析这些突变，我们阐明了两个PPO在体液黑化中的功能。我们的研究表明，PPO1和PPO2负责血淋巴中所有的PO活性。虽然PPO1参与了PO活性的快速早期传递，但PPOO2积累在晶体细胞的晶体中，并提供了一种可以在后期部署的存储形式。我们的研究还揭示了PPO1和PPO2在革兰氏阳性细菌和真菌感染后的生存中的重要作用，强调了黑化在昆虫宿主防御中的重要性。黑化反应是节肢动物的一种主要免疫反应，涉及感染和受伤部位黑色素的快速合成。黑化需要原酚氧化酶的激活，这是一种催化苯酚氧化成苯二酚的酶，苯二酚再聚合成黑色素。果蝇基因组包含三个编码酚氧化酶原(PPO)的基因。在这篇论文中，我们产生了携带PPO1和PPOO2基因缺失的果蝇。通过单独和联合分析这些突变，我们阐明了两种酚氧化酶原在体液黑化中的作用。我们报告说，PPO2组成了晶体细胞中的大部分晶体，晶体细胞是一种特定的血细胞类型。虽然PPO1和PPOO2都有助于昆虫血液中的酚氧化酶活性，但这些PPOO并不是完全多余的。我们的研究表明，PPO1参与了酚氧化酶活性的快速传递，而PPO2提供了一种可以在第二阶段部署的存储形式。关于黑化在果蝇宿主防御中的重要性，果蝇领域存在一些争议。我们的研究证明了PPO1和PPOO2在革兰氏阳性细菌和真菌感染后的存活中的重要作用，强调了黑化在昆虫免疫中的重要性。
The melanization reaction is a major immune response in Arthropods and involves the rapid synthesis of melanin at the site of infection and injury. A key enzyme in the melanization process is phenoloxidase (PO), which catalyzes the oxidation of phenols to quinones, which subsequently polymerize into melanin. The Drosophila genome encodes three POs, which are primarily produced as zymogens or prophenoloxidases (PPO). Two of them, PPO1 and PPO2, are produced by crystal cells. Here we have generated flies carrying deletions in PPO1 and PPO2. By analyzing these mutations alone and in combination, we clarify the functions of both PPOs in humoral melanization. Our study shows that PPO1 and PPO2 are responsible for all the PO activity in the hemolymph. While PPO1 is involved in the rapid early delivery of PO activity, PPO2 is accumulated in the crystals of crystal cells and provides a storage form that can be deployed in a later phase. Our study also reveals an important role for PPO1 and PPO2 in the survival to infection with Gram-positive bacteria and fungi, underlining the importance of melanization in insect host defense. The melanization reaction is a major immune response in Arthropods and involves the rapid synthesis of a black pigment, melanin, at the site of infection and injury. Melanization requires the activation of proPhenoloxidase, an enzyme that catalyzes the oxidation of phenols to quinones, which polymerize to melanin. The Drosophila genome contains three genes encoding prophenoloxidases (PPO). In this paper, we have generated flies carrying deletions in the PPO1 and PPO2 genes. By analyzing these mutations alone and in combination, we clarify the functions of both prophenoloxidases in humoral melanization. We report that PPO2 composes most of the crystals found in crystal cells, a specific hemocyte cell type. Although PPO1 and PPO2 both contribute to phenoloxidase activity in the insect blood, these PPOs are not fully redundant. Our study shows that PPO1 is involved in the rapid delivery of phenoloxidase activity when required, while PPO2 provides a storage form that can be deployed in a second phase. Some controversy exists in the Drosophila field about the importance of melanization in the Drosophila host defense. Our study demonstrates the important role of PPO1 and PPO2 in the survival to infection with both Gram-positive bacteria and fungi, underlining the importance of melanization in insect immunity.
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DOI：
10.1073/pnas.0903134106
发表时间：
2009-07-21
影响因子：
11.1
作者：
Ahmad, S. Tariq;Sweeney, Sean T.;Gao, Fen-Biao
通讯作者：
Gao, Fen-Biao
影响因子：
1.5
作者：
Gajewski, Kathleen M.;Sorrentino, Richard P.;Schulz, Robert A.
通讯作者：
Schulz, Robert A.
影响因子：
2.9
作者：
Eslin, Patrice;Doury, Geraldine
通讯作者：
Doury, Geraldine
DOI：
10.1073/pnas.0504982102
发表时间：
2005-08-09
影响因子：
11.1
作者：
Arakane, Y;Muthukrishnan, S;Kramer, KJ
通讯作者：
Kramer, KJ
影响因子：
16
作者：
Hedengren, M;Åsling, B;Hultmark, D
通讯作者：
Hultmark, D