Effect of levels of acetate on the mevalonate pathway of Borrelia burgdorferi.
Effect of levels of acetate on the mevalonate pathway of Borrelia burgdorferi.
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DOI：
10.1371/journal.pone.0038171
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发表时间：
2012
期刊：
影响因子：
3.7
通讯作者：
Seshu J
中科院分区：
文献类型：
--
作者：
Van Laar TA;Lin YH;Miller CL;Karna SL;Chambers JP;Seshu J
伯氏疏螺旋体是莱姆病的病原体，是一种代谢能力有限的螺旋体病原体，可在高度不同的宿主特异性条件下生存。然而，疏螺旋体基因组编码甲羟戊酸途径 (MP) 的几种蛋白质，该途径利用乙酰辅酶 A 作为底物，产生对肽聚糖生物合成和蛋白质翻译后修饰至关重要的中间代谢物。在这项研究中，我们分析了 MP 和醋酸盐在调节伯氏疏螺旋体适应性反应中的贡献。逆转录 PCR 显示 MP 的组成部分被转录为单独的开放阅读框。使用单特异性血清的免疫印迹分析证实了伯氏疏螺旋体中 MP 成员的合成。 MP 的限速步骤由 HMG-CoA 还原酶 (HMGR) 通过将 HMG-CoA 转化为甲羟戊酸来介导。重组疏螺旋体 HMGR 的 Km 值为 132 µM，Vmax 为 1.94 µmol NADPH 氧化分钟−1（毫克蛋白质）−1，并被他汀类药物抑制。在模拟喂食蜱（pH 6.8/37°C）的条件下生长的两种不同传染性伯氏疏螺旋体克隆分离株的总蛋白裂解物表现出HMGR水平升高，而MP的其他成员在未喂食蜱（pH 7.6/23°C）条件下升高。细胞外乙酸盐的增加导致 MP 蛋白以及 RpoS、CsrABb 及其各自负责介导脊椎动物宿主特异性适应的调节子水平升高。两种不同他汀类药物的内酯和酸形式均抑制伯氏疏螺旋体菌株 B31 的生长，而 HMGR 的过表达能够部分克服这种抑制作用。总之，这些关于 MP 和醋酸盐对宿主特异性适应的贡献的研究有助于确定潜在的代谢目标，这些目标可以被操纵以减少莱姆病的发病率。
Borrelia burgdorferi, the agent of Lyme disease, is a spirochetal pathogen with limited metabolic capabilities that survives under highly disparate host-specific conditions. However, the borrelial genome encodes several proteins of the mevalonate pathway (MP) that utilizes acetyl-CoA as a substrate leading to intermediate metabolites critical for biogenesis of peptidoglycan and post-translational modifications of proteins. In this study, we analyzed the MP and contributions of acetate in modulation of adaptive responses in B. burgdorferi. Reverse-transcription PCR revealed that components of the MP are transcribed as individual open reading frames. Immunoblot analysis using monospecific sera confirmed synthesis of members of the MP in B. burgdorferi. The rate-limiting step of the MP is mediated by HMG-CoA reductase (HMGR) via conversion of HMG-CoA to mevalonate. Recombinant borrelial HMGR exhibited a Km value of 132 µM with a Vmax of 1.94 µmol NADPH oxidized minute−1 (mg protein)−1 and was inhibited by statins. Total protein lysates from two different infectious, clonal isolates of B. burgdorferi grown under conditions that mimicked fed-ticks (pH 6.8/37°C) exhibited increased levels of HMGR while other members of the MP were elevated under unfed-tick (pH 7.6/23°C) conditions. Increased extra-cellular acetate gave rise to elevated levels of MP proteins along with RpoS, CsrABb and their respective regulons responsible for mediating vertebrate host-specific adaptation. Both lactone and acid forms of two different statins inhibited growth of B. burgdorferi strain B31, while overexpression of HMGR was able to partially overcome that inhibition. In summary, these studies on MP and contributions of acetate to host-specific adaptation have helped identify potential metabolic targets that can be manipulated to reduce the incidence of Lyme disease.
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影响因子：
3.1
作者：
Labandeira-Rey, M;Skare, JT
通讯作者：
Skare, JT
影响因子：
3.1
作者：
Karna, S. L. Rajasekhar;Sanjuan, Eva;Seshu, J.
通讯作者：
Seshu, J.
影响因子：
37.8
作者：
Bellosta, S;Paoletti, R;Corsini, A
通讯作者：
Corsini, A
DOI：
10.1073/pnas.231442498
发表时间：
2001-10-23
影响因子：
11.1
作者：
Hübner, A;Yang, XF;Norgard, MV
通讯作者：
Norgard, MV
影响因子：
12.3
作者：
Friesen JA;Rodwell VW
通讯作者：
Rodwell VW