Modified needle-tip PcrV proteins reveal distinct phenotypes relevant to the control of type III secretion and intoxication by Pseudomonas aeruginosa.
Modified needle-tip PcrV proteins reveal distinct phenotypes relevant to the control of type III secretion and intoxication by Pseudomonas aeruginosa.
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DOI：
10.1371/journal.pone.0018356
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发表时间：
2011-03-29
期刊：
影响因子：
3.7
通讯作者：
Frank DW
中科院分区：
文献类型：
--
作者：
Sato H;Hunt ML;Weiner JJ;Hansen AT;Frank DW
III型分泌系统（T3 SS）用于通过多种革兰氏阴性细菌（包括铜绿假单胞菌）将效应蛋白递送至真核宿主的胞质溶胶。效应子的易位依赖于由pcrGVHpopBD操纵子编码的蛋白质。这些蛋白质形成T3 S转运蛋白复合物，由针尖复合物（PcrV）、转座蛋白（PopB和PopD）和伴侣蛋白（PcrG和PcrH）组成。PcrV介导PopB/PopD在宿主质膜中的折叠和插入，其中组装的translocons形成易位通道。这种复合物的组装和效应物通过这种机制的递送受到PcrV的严格控制，但这种分子的多功能方面尚未确定。此外，PcrV是铜绿假单胞菌感染的保护性抗原，耶尔森氏菌的直系同源物LcrV也是如此。我们构建了含有框内接头插入和位点特异性突变的PcrV衍生物。这些衍生物的表达受PA 103的pcrV无效突变体中的T3 S特异性启动子的调控。九个衍生物破坏了调节效应分泌和组成型释放到生长培养基中的效应蛋白。这些调节突变体中的三个，其中接头插入在N-末端球状结构域中，能够将细胞毒素ExoU易位到真核宿主细胞中。我们还分离出表达延迟毒性表型的菌株，尽管效应子分泌水平正常，但其缓慢分泌易位子。大多数的细胞毒性易位能力的菌株保留的PcrV衍生物的保护性表位，和Mab 166能够保护红细胞在感染这些菌株。使用定义的PcrV衍生物具有不同的表型可能会导致更好地了解T3针尖蛋白的功能方面和治疗剂或靶向T3 SS介导的中毒疫苗的发展。
The type III secretion system (T3SS) is employed to deliver effector proteins to the cytosol of eukaryotic hosts by multiple species of Gram-negative bacteria, including Pseudomonas aeruginosa. Translocation of effectors is dependent on the proteins encoded by the pcrGVHpopBD operon. These proteins form a T3S translocator complex, composed of a needle-tip complex (PcrV), translocons (PopB and PopD), and chaperones (PcrG and PcrH). PcrV mediates the folding and insertion of PopB/PopD in host plasmic membranes, where assembled translocons form a translocation channel. Assembly of this complex and delivery of effectors through this machinery is tightly controlled by PcrV, yet the multifunctional aspects of this molecule have not been defined. In addition, PcrV is a protective antigen for P. aeruginosa infection as is the ortholog, LcrV, for Yersinia. We constructed PcrV derivatives containing in-frame linker insertions and site-specific mutations. The expression of these derivatives was regulated by a T3S-specific promoter in a pcrV-null mutant of PA103. Nine derivatives disrupted the regulation of effector secretion and constitutively released an effector protein into growth medium. Three of these regulatory mutants, in which the linker was inserted in the N-terminal globular domain, were competent for the translocation of a cytotoxin, ExoU, into eukaryotic host cells. We also isolated strains expressing a delayed-toxicity phenotype, which secrete translocators slowly despite the normal level of effector secretion. Most of the cytotoxic translocation-competent strains retained the protective epitope of PcrV derivatives, and Mab166 was able to protect erythrocytes during infection with these strains. The use of defined PcrV derivatives possessing distinct phenotypes may lead to a better understanding of the functional aspects of T3 needle-tip proteins and the development of therapeutic agents or vaccines targeting T3SS-mediated intoxication.
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DOI：
10.1083/jcb.147.3.683
发表时间：
1999-11-01
期刊：
The Journal of cell biology
影响因子：
--
作者：
Blocker A;Gounon P;Larquet E;Niebuhr K;Cabiaux V;Parsot C;Sansonetti P
通讯作者：
Sansonetti P
DOI：
10.1073/pnas.90.6.2320
发表时间：
1993-03-15
影响因子：
11.1
作者：
FU, H;COBURN, J;COLLIER, RJ
通讯作者：
COLLIER, RJ
影响因子：
5.7
作者：
Derewenda, U;Mateja, A;Waugh, DS
通讯作者：
Waugh, DS
影响因子：
3.1
作者：
Baer, Mark;Sawa, Teiji;Bebbington, Christopher
通讯作者：
Bebbington, Christopher
影响因子：
3.1
作者：
FRANK, DW;NAIR, G;SCHWEIZER, HP
通讯作者：
SCHWEIZER, HP