文献类型：期刊文献

英文题名：Phosphorylation of PppA at threonine 253 controls T6SS2 expression and bacterial killing capacity in the marine pathogen Vibrio alginolyticus

作者：Yang, Zhen[1];Wang, Xuetong[1];Xu, Wensheng[4];Zhou, Mian[1,2];Zhang, Yuanxing[1,2,3];Ma, Yue[1,3];Wang, Qiyao[1,2,3]

机构：[1]East China Univ Sci & Technol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China;[2]Shanghai Collaborat Innovat Ctr Biomfg, 130 Meilong Rd, Shanghai 200237, Peoples R China;[3]Shanghai Engn Res Ctr Maricultured Anim Vaccines, Shanghai, Peoples R China;[4]Beijing Univ Agr, Food Sci & Engn Coll, Beijing 102206, Peoples R China

年份：2018

卷号：209

起止页码：70

外文期刊名：MICROBIOLOGICAL RESEARCH

收录：;EI(收录号：20180904839258);WOS:【SCI-EXPANDED(收录号:WOS:000431471600007)】；

基金：This work was supported by grants from National Natural Science Foundation of China (Nos. 31772891 to QW, 31772893 to YM, 41376128 to YZ), the Ministry of Agriculture of China (CARS-47-G17), the Shanghai Pujiang Program (16PJD018), the Science and Technology Commission of Shandong and Shanghai Municipality (2017CXGC0103 and 17391902000), and Beijing Municipal Commission of Education (KM201310020010).

语种：英文

外文关键词：T6SS2; Vibrio alginolyticus; PppA; QS; Bacterial killing

摘要：Type VI secretion systems (T6SSs) are multi-protein secretory nano-machines that mediate inter-bacterial competition. Vibrio alginolyticus is an abundant gram-negative marine bacterium that efficiently kills other bacteria with its T6SS2. The V. alginolyticus T6SS2 gene cluster encodes a phosphatase, PppA, and a type II membrane-spanning Hanks-type threonine kinase, PpkA2, which have been implicated in the activation of T6S. Meanwhile, T6SS2 gene expression is under the control of quorum sensing. However, the role of PppA in T6SS2 activity is unclear. Here, our phosphoproteomic screen identified PppA as a novel PpkA2 substrate. Phosphorylation at threonine 253 (T253) of PppA is not conserved in other bacteria, suggesting that PppA may play a unique role in T6SS2 activation in V. alginolyticus. Interestingly, PppA phosphatase activity was modulated by the cognate kinase PpkA2, which implied that a homeostasis is required for optimal T6S activity. PppA and phosphorylation of PppA at T253 are important for T6S activity and T6SS2-mediated bacterial killing. Moreover, PppA and the phosphorylation of PppA are also essential for the expression of LuxR, the master regulator of quorum sensing, thus augmenting T6SS2 expression. Collectively, our data demonstrated that phosphorylation of PppA at T253 controls the activity of T6SS2, thereby enhancing the competitive fitness of V. alginolyticus.