Expression of Ralstonia solanacearum type III secretion system is dependent on a novel type 4 pili (T4P) assembly protein (TapV) but is T4P independent
Expression of Ralstonia solanacearum type III secretion system is dependent on a novel type 4 pili (T4P) assembly protein (TapV) but is T4P independent
复制标题
Ralstonia solanacearum III 型分泌系统的表达依赖于新型 4 型菌毛 (T4P) 组装蛋白 (TapV)，但不依赖于 T4P
DOI：
10.1111/mpp.12930
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发表时间：
2020-03
影响因子：
4.9
通讯作者：
Ohnishi Kouhei
中科院分区：
文献类型：
--
作者：
Zhang Yong;Han Liangliang;Zhang Lichun;Xu Changzheng;Shi Xiaojun;Hikichi Yasufumi;Ohnishi Kouhei
IV型菌毛(T4P)是动植物多种病原菌中的毒力因子，在抽动运动、游泳运动、生物膜形成和与宿主细胞的黏附中发挥重要作用。在这里，我们研究了一个可能的T4P装配蛋白TAPV(参考菌株GMI1000中的Rsc1986)及其同源物Rsp0189在青枯雷尔氏菌中的功能，该蛋白与TAPV有58%的氨基酸同源性。TAPV的缺失，而不是rsp0189的缺失，导致了番茄的抽动运动、游泳运动和对番茄根的粘附性显著降低，这与Pila突变体(一个已知的青枯病菌T4P缺失突变体)的表型一致。然而，与Pila突变体不同的是，TAPV突变体比野生型菌株产生更多的生物膜。我们的基因表达研究表明，TAPV而不是Rsp0189对于III型分泌系统(T3SS，青枯病菌的致病决定因素)在体外和植物中的表达都是重要的，但它不依赖于T4P。我们进一步揭示了TAPV通过PhcA-TAPV-PrhG-HrpB途径影响T3SS的表达，这与以往报道的PhcA正向调节Pila和PrhG的表达一致。此外，缺失TAPV而不是rsp0189显著削弱了寄主植物木质部导管的迁移和定植能力，但青枯病菌在烟草叶片中的细胞间增殖没有改变，这与Pila突变体相似。TAPV突变体在寄主植物上表现出明显的毒力减弱。这是关于T4P组分对T3SS影响的首次报道，为我们理解T4P的各种生物学功能以及T3SS在青枯菌中的复杂调控途径提供了新的见解。
Abstract Type IV pili (T4P) are virulence factors in various pathogenic bacteria of animals and plants that play important roles in twitching motility, swimming motility, biofilm formation, and adhesion to host cells. Here, we genetically characterized functional roles of a putative T4P assembly protein TapV (Rsc1986 in reference strain GMI1000) and its homologue Rsp0189, which shares 58% amino acid identity with TapV, in Ralstonia solanacearum. Deletion of tapV, but not rsp0189, resulted in significantly impaired twitching motility, swimming motility, and adhesion to tomato roots, which are consistent as phenotypes of the pilA mutant (a known R. solanacearum T4P‐deficient mutant). However, unlike the pilA mutant, the tapV mutant produced more biofilm than the wild‐type strain. Our gene expression studies revealed that TapV, but not Rsp0189, is important for expression of a type III secretion system (T3SS, a pathogenicity determinant of R. solanacearum) both in vitro and in planta, but it is T4P independent. We further revealed that TapV affected the T3SS expression via the PhcA–TapV–PrhG–HrpB pathway, consistent with previous reports that PhcA positively regulates expression of pilA and prhG. Moreover, deletion of tapV, but not rsp0189, significantly impaired the ability to migrate into and colonize xylem vessels of host plants, but there was no alteration in intercellular proliferation of R. solanacearum in tobacco leaves, which is similar to the pilA mutant. The tapV mutant showed significantly impaired virulence in host plants. This is the first report on the impact of T4P components on the T3SS, providing novel insights into our understanding of various biological functions of T4P and the complex regulatory pathway of T3SS in R. solanacearum.
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影响因子：
4.5
作者：
D. Robinson;Peter Oliviusson;G. Hinz
通讯作者：
D. Robinson;Peter Oliviusson;G. Hinz
影响因子：
2.1
作者：
Yong Zhang;A. Kiba;Y. Hikichi;K. Ohnishi
通讯作者：
Yong Zhang;A. Kiba;Y. Hikichi;K. Ohnishi
影响因子：
5.6
作者：
Hikichi Y;Mori Y;Ishikawa S;Hayashi K;Ohnishi K;Kiba A;Kai K
通讯作者：
Kai K
影响因子：
3.5
作者：
Poueymiro, Marie;Cunnac, Sebastien;Genin, Stephane
通讯作者：
Genin, Stephane
影响因子：
2.8
作者：
BRADLEY, DE
通讯作者：
BRADLEY, DE