Vibrio parahaemolyticus type VI secretion system 1 is activated in marine conditions to target bacteria, and is differentially regulated from system 2.
Vibrio parahaemolyticus type VI secretion system 1 is activated in marine conditions to target bacteria, and is differentially regulated from system 2.
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DOI：
10.1371/journal.pone.0061086
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发表时间：
2013
期刊：
影响因子：
3.7
通讯作者：
Orth K
中科院分区：
文献类型：
--
作者：
Salomon D;Gonzalez H;Updegraff BL;Orth K
副溶血性弧菌是一种海洋细菌，在温暖的气候中茁壮成长。它是进食受污染的生贝类海产引致肠胃炎的主要原因。该细菌具有两个推定的VI型分泌系统（T6SS）。T6SS是在许多革兰氏阴性细菌中发现的广泛的蛋白质分泌系统，并且通常受到严格调控。对于迄今为止研究的许多T6SS，条件和线索，以及控制T6SS活性的调节机制是未知的。在这项研究中，我们表征了激活副溶血性弧菌T6SS的环境条件和线索，并确定了控制T6SS基因表达和活性的调控机制。我们监测的签名T6SS分泌蛋白Hcp1和Hcp2的表达和分泌，发现这两个T6SS的差异调节群体感应和表面感应。我们还发现，T6SS1和T6SS2需要不同的温度和盐度条件才能活跃。有趣的是，主要在临床分离株中发现的T6SS1在温暖的海洋条件下最活跃。此外，我们发现T6SS 1在这些条件下具有抗菌活性。此外，我们在T6SS1基因簇中确定了两个转录调节因子，它们调节Hcp1的表达，但对自身中毒的免疫力不是必需的。对环境分离株的进一步研究揭示了T6SS1的存在与副溶血性弧菌对其他细菌的毒力之间的相关性，我们还表明不同的副溶血性弧菌分离株可以相互竞争。我们建议T6SS1和T6SS2在副溶血弧菌的生活方式中发挥不同的作用，并建议T6SS1在海洋环境中增强副溶血弧菌的环境适应性时，在其他细菌种群的存在下竞争一个生态位。
Vibrio parahaemolyticus is a marine bacterium that thrives in warm climates. It is a leading cause of gastroenteritis resulting from consumption of contaminated uncooked shellfish. This bacterium harbors two putative type VI secretion systems (T6SS). T6SSs are widespread protein secretion systems found in many Gram-negative bacteria, and are often tightly regulated. For many T6SSs studied to date, the conditions and cues, as well as the regulatory mechanisms that control T6SS activity are unknown. In this study, we characterized the environmental conditions and cues that activate both V. parahaemolyticus T6SSs, and identified regulatory mechanisms that control T6SS gene expression and activity. We monitored the expression and secretion of the signature T6SS secreted proteins Hcp1 and Hcp2, and found that both T6SSs are differentially regulated by quorum sensing and surface sensing. We also showed that T6SS1 and T6SS2 require different temperature and salinity conditions to be active. Interestingly, T6SS1, which is found predominantly in clinical isolates, was most active under warm marine-like conditions. Moreover, we found that T6SS1 has anti-bacterial activity under these conditions. In addition, we identified two transcription regulators in the T6SS1 gene cluster that regulate Hcp1 expression, but are not required for immunity against self-intoxication. Further examination of environmental isolates revealed a correlation between the presence of T6SS1 and virulence of V. parahaemolyticus against other bacteria, and we also showed that different V. parahaemolyticus isolates can outcompete each other. We propose that T6SS1 and T6SS2 play different roles in the V. parahaemolyticus lifestyles, and suggest a role for T6SS1 in enhancing environmental fitness of V. parahaemolyticus in marine environments when competing for a niche in the presence of other bacterial populations.
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影响因子：
3.6
作者：
Gode-Potratz CJ;Kustusch RJ;Breheny PJ;Weiss DS;McCarter LL
通讯作者：
McCarter LL
影响因子：
6.4
作者：
Daniels, NA;MacKinnon, L;Slutsker, L
通讯作者：
Slutsker, L
影响因子：
2.4
作者：
Furukawa, Yuichiro;Hasegawa, Hiroshi
通讯作者：
Hasegawa, Hiroshi
影响因子：
4.4
作者：
Martinez-Urtaza, Jaime;Lozano-Leon, Antonio;Garcia-Martin, Oscar
通讯作者：
Garcia-Martin, Oscar
弧菌性溶血性细胞生物学和致病性决定因素。
影响因子：
5.8
作者：
Broberg CA;Calder TJ;Orth K
通讯作者：
Orth K