Peptidoglycan-modifying enzyme Pgp1 is required for helical cell shape and pathogenicity traits in Campylobacter jejuni.
Peptidoglycan-modifying enzyme Pgp1 is required for helical cell shape and pathogenicity traits in Campylobacter jejuni.
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DOI：
10.1371/journal.ppat.1002602
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发表时间：
2012
期刊：
影响因子：
6.7
通讯作者：
Gaynor EC
中科院分区：
文献类型：
--
作者：
Frirdich E;Biboy J;Adams C;Lee J;Ellermeier J;Gielda LD;Dirita VJ;Girardin SE;Vollmer W;Gaynor EC
细菌形态对病原体毒力和传播属性的影响知之甚少。流行的肠道病原体空肠弯曲杆菌显示出螺旋形状，假定其对于定殖和宿主相互作用是重要的。然而，这一点以前从未在实验中得到证实。C.因此，空肠是探索螺旋形态调节因子在发病机制中的作用的良好生物体。我们确定了一个未表征的基因，命名为pgp 1（肽聚糖肽酶1），在钙荧光素白色为基础的屏幕，探索细胞包膜的性质重要的C。空肠毒力和应激存活。生物信息学研究表明，Pgp 1主要在弯曲和螺旋细菌中保守。pgp 1的缺失导致了一个引人注目的杆状形态，使pgp 1成为第一个C。jejuni基因参与了C.空肠细胞形态。pgp 1参与关键的致病和细胞包膜表型。与野生型相比，杆状pgp 1突变体在鸡定植中缺陷超过三个数量级，并引起上皮细胞感染中趋化因子IL-8的分泌增强。pgp 1突变体和pgp 1过表达菌株（同样产生直细胞或扭结细胞）均表现出生物膜和运动缺陷。通过HPLC和质谱法进行的详细肽聚糖分析，以及Pgp 1酶测定，证实Pgp 1是一种新型肽聚糖DL-羧肽酶，可将单体三肽裂解为二肽。从pgp 1突变体的肽聚糖激活宿主细胞受体Nod 1在更大程度上比野生型。这项工作提供了一个C。jejuni基因和形态、肽聚糖生物合成以及关键宿主和传播相关特征。细菌细胞的形状取决于细胞被膜成分肽聚糖的组成。一些重要的病原体具有特征性的螺旋状形态，这可能有助于它们钻入覆盖粘液的细胞中以启动定植和致病性。一个例子是空肠弯曲杆菌，它是发达国家细菌引起的结肠炎的主要原因。直接证据支持的假设，C。空肠的形状与其致病性性状有关，以前尚未提供。我们鉴定了一个编码肽酶修饰肽聚糖的基因，该肽聚糖对维持C。空肠螺旋形。我们现在可以连接C。jejuni基因与形态学和肽聚糖生物合成的关系。该基因的缺失也被发现影响致病属性，如鸡定植，生物膜，运动性和宿主炎症介质的激活。此外，这是第一个研究彻底表征C。空肠肽聚糖结构，并鉴定参与肽聚糖维持的基因。我们的研究结果突出了细菌发病机制研究中的一个新兴主题：细菌细胞生物学和发病机制之间的联系。最后，我们对C.空肠细胞形状和肽聚糖的研究为C.空肠和其他弯曲和螺旋形态的细菌。
The impact of bacterial morphology on virulence and transmission attributes of pathogens is poorly understood. The prevalent enteric pathogen Campylobacter jejuni displays a helical shape postulated as important for colonization and host interactions. However, this had not previously been demonstrated experimentally. C. jejuni is thus a good organism for exploring the role of factors modulating helical morphology on pathogenesis. We identified an uncharacterized gene, designated pgp1 (peptidoglycan peptidase 1), in a calcofluor white-based screen to explore cell envelope properties important for C. jejuni virulence and stress survival. Bioinformatics showed that Pgp1 is conserved primarily in curved and helical bacteria. Deletion of pgp1 resulted in a striking, rod-shaped morphology, making pgp1 the first C. jejuni gene shown to be involved in maintenance of C. jejuni cell shape. Pgp1 contributes to key pathogenic and cell envelope phenotypes. In comparison to wild type, the rod-shaped pgp1 mutant was deficient in chick colonization by over three orders of magnitude and elicited enhanced secretion of the chemokine IL-8 in epithelial cell infections. Both the pgp1 mutant and a pgp1 overexpressing strain – which similarly produced straight or kinked cells – exhibited biofilm and motility defects. Detailed peptidoglycan analyses via HPLC and mass spectrometry, as well as Pgp1 enzyme assays, confirmed Pgp1 as a novel peptidoglycan DL-carboxypeptidase cleaving monomeric tripeptides to dipeptides. Peptidoglycan from the pgp1 mutant activated the host cell receptor Nod1 to a greater extent than did that of wild type. This work provides the first link between a C. jejuni gene and morphology, peptidoglycan biosynthesis, and key host- and transmission-related characteristics. Bacterial cell shape is dictated by the composition of the cell envelope component peptidoglycan. Some important pathogens have a characteristic helical corkscrew morphology that may help them burrow into mucus overlaying cells to initiate colonization and pathogenicity. One example is Campylobacter jejuni, the leading cause of bacterial-induced diarrheal disease in the developed world. Direct evidence supporting the hypothesis that C. jejuni shape is related to its pathogenicity traits has not previously been provided. We identified a gene encoding a peptidase modifying peptidoglycan that is essential for maintaining the C. jejuni corkscrew shape. We can now connect a C. jejuni gene with morphology and peptidoglycan biosynthesis. Loss of this gene was also found to affect pathogenic attributes such as chicken colonization, biofilms, motility, and activation of host inflammatory mediators. In addition, this is the first study to thoroughly characterize C. jejuni peptidoglycan structure and to identify a gene involved in peptidoglycan maintenance. Our findings highlight an emerging theme in bacterial pathogenesis research: the connection between bacterial cell biology and pathogenesis. Finally, our characterization of C. jejuni cell shape and peptidoglycan provides a starting point for further work in this area in C. jejuni and other bacteria with curved and helical morphologies.
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DOI：
10.1111/j.1432-1033.1985.tb08873.x
发表时间：
1985-01-01
期刊：
EUROPEAN JOURNAL OF BIOCHEMISTRY
影响因子：
--
作者：
GARNIER, M;VACHERON, MJ;MICHEL, G
通讯作者：
MICHEL, G
影响因子：
4.8
作者：
Hasegawa, Mizuho;Yang, Kangkang;Inohara, Naohiro
通讯作者：
Inohara, Naohiro
DOI：
10.1111/j.1432-1033.1977.tb11351.x
发表时间：
1977-01-01
期刊：
EUROPEAN JOURNAL OF BIOCHEMISTRY
影响因子：
--
作者：
ARMINJON, F;GUINAND, M;MICHEL, G
通讯作者：
MICHEL, G
影响因子：
2.6
作者：
AMANO, K;SHIBATA, Y
通讯作者：
SHIBATA, Y
影响因子：
3.2
作者：
Costa, K;Bacher, G;García-del Portillo, F
通讯作者：
García-del Portillo, F