ArsRS-Dependent Regulation of homB Contributes to Helicobacter pylori Biofilm Formation.
ArsRS-Dependent Regulation of homB Contributes to Helicobacter pylori Biofilm Formation.
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DOI：
10.3389/fmicb.2018.01497
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发表时间：
2018
影响因子：
5.2
通讯作者：
Merrell DS
中科院分区：
文献类型：
--
作者：
Servetas SL;Doster RS;Kim A;Windham IH;Cha JH;Gaddy JA;Merrell DS
幽门螺杆菌领域的一个难以捉摸的领域是了解为什么某些感染会导致胃癌，而另一些感染则在个体的一生中无症状地持续存在。甚至在基因组时代之前，幽门螺杆菌的高水平种内多样性就已得到充分认识，并成为疾病进展方面一个有趣的研究领域。在这方面令人感兴趣的是超过 60 种外膜蛋白 (OMP) 的独特功能，其中一些与疾病结果相关。在这些 OMP 中，HomB 与疾病结果之间的关联因所研究的人群而异。虽然已经评估了一些与疾病相关的 OMP 的分子作用，但人们对 HomB 在幽门螺杆菌生命周期中所起的作用知之甚少。因此，在此我们研究了 homB 表达、调节以及对生物膜形成的贡献。我们发现，在幽门螺杆菌G27菌株中，homB在稳定期之前以相对较低的水平表达。此外，homB 表达在低 pH 条件下以 ArsRS 依赖性方式受到抑制； arsRS 的突变导致所有测试时间点的 homB 转录物增加。 ArsRS 对 homB 的调节似乎是直接的，因为纯化的 ArsR 能够特异性结合 homB 启动子。这一调节与我们之前发现的 ArsRS 突变导致生物膜形成增强相结合，使我们检验了 homB 有助于幽门螺杆菌生物膜形成的假设。事实上，随后使用结晶紫定量测定和扫描电子显微镜 (SEM) 进行的生物膜分析表明，超生物膜形成菌株中 homB 的丢失导致恢复为模仿野生型的生物膜表型。此外，即使在 homB 染色体拷贝已被删除的菌株中，从取消 ArsRS 调节的启动子反式表达 homB 也会导致生物膜形成增强。因此，homB 对于 ArsRS 突变株的超生物膜形成是必需的，并且该基因的异常调节足以诱导超生物膜表型。总之，这些数据表明，OMP（例如 HomB）的 ArsRS 依赖性调节可能是 ArsRS 以 pH 响应方式指示生物膜发育的一种机制。
One elusive area in the Helicobacter pylori field is an understanding of why some infections result in gastric cancer, yet others persist asymptomatically for the life-span of the individual. Even before the genomic era, the high level of intraspecies diversity of H. pylori was well recognized and became an intriguing area of investigation with respect to disease progression. Of interest in this regard is the unique repertoire of over 60 outer membrane proteins (OMPs), several of which have been associated with disease outcome. Of these OMPs, the association between HomB and disease outcome varies based on the population being studied. While the molecular roles for some of the disease-associated OMPs have been evaluated, little is known about the role that HomB plays in the H. pylori lifecycle. Thus, herein we investigated homB expression, regulation, and contribution to biofilm formation. We found that in H. pylori strain G27, homB was expressed at a relatively low level until stationary phase. Furthermore, homB expression was suppressed at low pH in an ArsRS-dependent manner; mutation of arsRS resulted in increased homB transcript at all tested time-points. ArsRS regulation of homB appeared to be direct as purified ArsR was able to specifically bind to the homB promoter. This regulation, combined with our previous finding that ArsRS mutations lead to enhanced biofilm formation, led us to test the hypothesis that homB contributes to biofilm formation by H. pylori. Indeed, subsequent biofilm analysis using a crystal-violet quantification assay and scanning electron microscopy (SEM) revealed that loss of homB from hyper-biofilm forming strains resulted in reversion to a biofilm phenotype that mimicked wild-type. Furthermore, expression of homB in trans from a promoter that negated ArsRS regulation led to enhanced biofilm formation even in strains in which the chromosomal copy of homB had been deleted. Thus, homB is necessary for hyper-biofilm formation of ArsRS mutant strains and aberrant regulation of this gene is sufficient to induce a hyper-biofilm phenotype. In summary, these data suggest that the ArsRS-dependent regulation of OMPs such as HomB may be one mechanism by which ArsRS dictates biofilm development in a pH responsive manner.
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DOI：
10.1099/mic.0.2007/016055-0
发表时间：
2008-08
期刊：
Microbiology (Reading, England)
影响因子：
--
作者：
Goodwin AC;Weinberger DM;Ford CB;Nelson JC;Snider JD;Hall JD;Paules CI;Peek RM;Forsyth MH
通讯作者：
Forsyth MH
影响因子：
4.4
作者：
Goh KL;Chan WK;Shiota S;Yamaoka Y
通讯作者：
Yamaoka Y
影响因子：
5.2
作者：
Jones KR;Whitmire JM;Merrell DS
通讯作者：
Merrell DS
影响因子：
6.7
作者：
Hussein, Nawfal R
通讯作者：
Hussein, Nawfal R
影响因子：
12.6
作者：
Cammarota, Giovanni;Branca, Giovanna;Gasbarrini, Giovanni
通讯作者：
Gasbarrini, Giovanni