Regulation of rugosity and biofilm formation in Vibrio cholerae:: Comparison of VpsT and VpsR regulons and epistasis analysis of vpsT, vpsR, and hapR
Regulation of rugosity and biofilm formation in Vibrio cholerae:: Comparison of VpsT and VpsR regulons and epistasis analysis of vpsT, vpsR, and hapR
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DOI：
10.1128/jb.00981-06
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发表时间：
2007-01-01
影响因子：
3.2
通讯作者：
Yildiz, Fitnat H.
中科院分区：
文献类型：
--
作者：
Beyhan, Sinem;Bilecen, Kivanc;Yildiz, Fitnat H.
霍乱弧菌经历表型变异，产生两种形态上不同的变体，称为光滑和皱纹。这两种变体的转录谱差异很大，许多差异调节的基因由复杂的调节电路控制，包括转录调节因子VpsR，VpsT和HapR。在这项研究中，我们鉴定了VpsT调节子，并比较了VpsT和VpsR调节子，以阐明每个正调节子对皱纹变体转录谱和相关表型的贡献。我们已经发现，虽然VpsT和VpsR调节子非常相似，但每个调节子完成的基因调节的幅度是不同的。我们还确定，cdgA，它编码GGDEF结构域蛋白，是部分负责vpsT和vpsR突变体之间的vps基因表达的改变。hapR，vpsT，和vpsR之间的上位性关系的分析，相对于全基因组表达谱，菌落形态，和生物膜形成揭示，vpsR是上位性的hapR和vpsT。相对于hapR突变体，vpsR hapR双突变体中毒力基因的表达增加，表明VpsR负调控hapR突变体中毒力基因的表达。这些结果表明，VpsT、VpsR、HapR和GGDEF/EAL家族蛋白之间的复杂调节相互作用控制霍乱弧菌中弧菌多糖和毒力因子产生所需的基因的转录。
Vibrio cholerae undergoes phenotypic variation that generates two morphologically different variants, termed smooth and rugose. The transcriptional profiles of the two variants differ greatly, and many of the differentially regulated genes are controlled by a complex regulatory circuitry that includes the transcriptional regulators VpsR, VpsT, and HapR. In this study, we identified the VpsT regulon and compared the VpsT and VpsR regulons to elucidate the contribution of each positive regulator to the rugose variant transcriptional profile and associated phenotypes. We have found that although the VpsT and VpsR regulons are very similar, the magnitude of the gene regulation accomplished by each regulator is different. We also determined that cdgA, which encodes a GGDEF domain protein, is partially responsible for the altered vps gene expression between the vpsT and vpsR mutants. Analysis of epistatic relationships among hapR, vpsT, and vpsR with respect to a whole-genome expression profile, colony morphology, and biofilm formation revealed that vpsR is epistatic to hapR and vpsT. Expression of virulence genes was increased in a vpsR hapR double mutant relative to a hapR mutant, suggesting that VpsR negatively regulates virulence gene expression in the hapR mutant. These results show that a complex regulatory interplay among VpsT, VpsR, HapR, and GGDEF/EAL family proteins controls transcription of the genes required for Vibrio polysaccharide and virulence factor production in V. cholerae.