Bifidobacteria exhibit LuxS-dependent autoinducer 2 activity and biofilm formation.
Bifidobacteria exhibit LuxS-dependent autoinducer 2 activity and biofilm formation.
复制标题
DOI：
10.1371/journal.pone.0088260
复制
发表时间：
2014
期刊：
影响因子：
3.7
通讯作者：
Riedel CU
中科院分区：
文献类型：
--
作者：
Sun Z;He X;Brancaccio VF;Yuan J;Riedel CU
自诱导剂-2 （AI-2）分子是一类信号分子，参与依赖于种群密度的基因调控，这种机制通常被称为群体感应（QS）。AI-2由甲基硫代腺苷/ s -腺苷-同型半胱氨酸核苷酶LuxS产生。在目前的研究中，我们描述了双歧杆菌LuxS蛋白的功能，以解决这些经济上重要的细菌是否能够进行QS通信的问题。所有公开的双歧杆菌基因组序列都含有假定的luxS基因。推导出的氨基酸序列在该属中具有较好的保守性，与典型的AI-2产生菌哈维弧菌的LuxS蛋白具有良好的同源性。3株双歧杆菌luxS基因在ai -2阴性的大肠杆菌DH5α中成功表达。这些重组大肠杆菌菌株的上清液具有显著的AI-2活性。在最初的实验中，我们未能在MRSc中培养的双歧杆菌上清液中检测到AI-2的活性。高浓度葡萄糖和酸性pH对AI-2活性有较强的抑制作用。当使用较少量的上清液时，可以检测到AI-2活性。在长双歧杆菌NCC2705中同源过表达luxS使上清中AI-2水平升高。此外，过表达luxS或添加含有ai -2的上清液可增强长叶假丝酵母NCC2705的生物膜形成。总的来说，这些结果表明双歧杆菌确实含有参与产生ai -2样分子的功能luxS基因。据我们所知，这是关于双歧杆菌产生AI-2活性的第一份报告。肠道内其他细菌自身产生的AI-2活性以及AI-2样分子可能对双歧杆菌的生物膜形成和寄主定植具有调节作用。
Autoinducer-2 (AI-2) molecules are one class of signalling molecules involved in gene regulation dependent on population density in a mechanism commonly referred to as quorum sensing (QS). AI-2 is produced by the methylthioadenosine/S-adenosyl-homocysteine nucleosidase LuxS. In the present study, we characterise the function of bifidobacterial LuxS proteins to address the question whether these economically important bacteria are able to perform QS communication. All publically available genome sequences of bifidobacteria harbour putative luxS genes. The deduced amino acid sequences are well conserved in the genus and show good homology to the LuxS protein of the prototypical AI-2 producer Vibrio harveyi. The luxS genes of three bifidobacterial strains were successfully expressed in AI-2-negative Escherichia coli DH5α. Supernatants of these recombinant E. coli strains contained significant AI-2 activity. In initial experiments, we failed to detect AI-2 activity in supernatants of bifidobacteria grown in MRSc. High concentration of glucose as well as acidic pH had strong inhibitory effects on AI-2 activity. AI-2 activity could be detected when lower volumes of supernatants were used in the assay. Homologous overexpression of luxS in Bifidobacterium longum NCC2705 increased AI-2 levels in the supernatant. Furthermore, over-expression of luxS or supplementation with AI-2-containing supernatants enhanced biofilm formation of B. longum NCC2705. Collectively, these results suggest that bifidobacteria indeed harbour functional luxS genes that are involved in the production of AI-2-like molecules. To the best of our knowledge, this represents the first report on AI-2 activity produced by bifidobacteria. Self-produced AI-2 activity as well as AI-2-like molecules of other bacteria of the intestinal tract may have a regulatory function in biofilm formation and host colonization by bifidobacteria.
登录
查看更多内容
影响因子：
10.7
作者：
Lerat, E;Moran, NA
通讯作者：
Moran, NA
影响因子：
3.6
作者：
BASSLER, BL;WRIGHT, M;SILVERMAN, MR
通讯作者：
SILVERMAN, MR
影响因子：
3.6
作者：
BASSLER, BL;WRIGHT, M;SILVERMAN, MR
通讯作者：
SILVERMAN, MR
影响因子：
2.2
作者：
Turovskiy, Yevgeniy;Chikindas, Michael L.
通讯作者：
Chikindas, Michael L.
影响因子：
3.6
作者：
Riedel, Christian U.;Monk, Ian R.;Hill, Colin
通讯作者：
Hill, Colin