Overexpression of VpsS, a Hybrid Sensor Kinase, Enhances Biofilm Formation in Vibrio cholerae
Overexpression of VpsS, a Hybrid Sensor Kinase, Enhances Biofilm Formation in Vibrio cholerae
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DOI：
10.1128/jb.00401-09
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发表时间：
2009-08-15
影响因子：
3.2
通讯作者：
Yildiz, Fitnat H.
中科院分区：
文献类型：
--
作者：
Shikuma, Nicholas J.;Fong, Jiunn C. N.;Yildiz, Fitnat H.
霍乱弧菌引起霍乱并栖息在水生环境中。霍乱弧菌在环境中生存的一个关键因素是它能够形成基质封闭的表面相关微生物群落，称为生物膜。成熟的生物膜依靠弧菌多糖将细胞彼此连接并连接到表面。我们先前描述了一个核心调控网络，它由两个正转录调节因子，VpsR和VpsT，和一个负转录调节因子HapR，控制生物膜的形成，通过调节vps基因的表达。在这项研究中，我们报告的传感器组氨酸激酶，VpsS，它可以控制生物膜的形成和激活vps基因的表达的鉴定。VpsS需要响应调节因子VpsR来激活vps表达。VpsS是一种混合传感器组氨酸激酶，预计含有组氨酸激酶和反应调节结构域，但缺乏组氨酸磷酸转移酶（HPT）结构域。我们确定VpsS通过HPT蛋白LuxU起作用，LuxU参与霍乱弧菌中的群体感应信号转导网络。体外磷酸转移关系分析表明，LuxU可以特异性逆转磷酸转移到CqsS，LuxQ和VpsS。此外，突变和表型分析表明，VpsS需要响应调节器LuxO激活vps表达，LuxO正调控vpsR和vpsT的转录。通过VpsS诱导vps表达也显示独立于HapR发生。因此，VpsS利用群体感应途径的组分来调节霍乱弧菌中的生物膜形成。
Vibrio cholerae causes the disease cholera and inhabits aquatic environments. One key factor in the environmental survival of V. cholerae is its ability to form matrix-enclosed, surface-associated microbial communities known as biofilms. Mature biofilms rely on Vibrio polysaccharide to connect cells to each other and to a surface. We previously described a core regulatory network, which consists of two positive transcriptional regulators, VpsR and VpsT, and a negative transcriptional regulator HapR, that controls biofilm formation by regulating the expression of vps genes. In this study, we report the identification of a sensor histidine kinase, VpsS, which can control biofilm formation and activates the expression of vps genes. VpsS required the response regulator VpsR to activate vps expression. VpsS is a hybrid sensor histidine kinase that is predicted to contain both histidine kinase and response regulator domains, but it lacks a histidine phosphotransferase (HPT) domain. We determined that VpsS acts through the HPT protein LuxU, which is involved in a quorum-sensing signal transduction network in V. cholerae. In vitro analysis of phosphotransfer relationships revealed that LuxU can specifically reverse phosphotransfer to CqsS, LuxQ, and VpsS. Furthermore, mutational and phenotypic analyses revealed that VpsS requires the response regulator LuxO to activate vps expression, and LuxO positively regulates the transcription of vpsR and vpsT. The induction of vps expression via VpsS was also shown to occur independent of HapR. Thus, VpsS utilizes components of the quorum-sensing pathway to modulate biofilm formation in V. cholerae.