scholarly journals Type VI secretion systems of plant‐pathogenic Burkholderia glumae BGR1 play a functionally distinct role in interspecies interactions and virulence

2020 ◽  
Vol 21 (8) ◽  
pp. 1055-1069 ◽  
Author(s):  
Namgyu Kim ◽  
Jin Ju Kim ◽  
Inyoung Kim ◽  
Mohamed Mannaa ◽  
Jungwook Park ◽  
...  
Keyword(s):  
Interspecies Interactions ◽  
Secretion Systems ◽  
Burkholderia Glumae ◽  
Type Vi Secretion ◽  
Distinct Role

scholarly journals T6SS Mediated Stress Responses for Bacterial Environmental Survival and Host Adaptation

2021 ◽  
Vol 22 (2) ◽  
pp. 478
Author(s):  
Kai-Wei Yu ◽  
Peng Xue ◽  
Yang Fu ◽  
Liang Yang
Keyword(s):  
Protein Secretion ◽  
Stress Responses ◽  
Current Knowledge ◽  
Bacterial Species ◽  
Host Cells ◽  
Interspecies Interactions ◽  
Type Vi Secretion System ◽  
Membrane Complex ◽  
Type Vi Secretion ◽  
Bacterial Type

The bacterial type VI secretion system (T6SS) is a protein secretion apparatus widely distributed in Gram-negative bacterial species. Many bacterial pathogens employ T6SS to compete with the host and to coordinate the invasion process. The T6SS apparatus consists of a membrane complex and an inner tail tube-like structure that is surrounded by a contractile sheath and capped with a spike complex. A series of antibacterial or antieukaryotic effectors is delivered by the puncturing device consisting of a Hcp tube decorated by the VgrG/PAAR complex into the target following the contraction of the TssB/C sheath, which often leads to damage and death of the competitor and/or host cells. As a tool for protein secretion and interspecies interactions, T6SS can be triggered by many different mechanisms to respond to various physiological conditions. This review summarizes our current knowledge of T6SS in coordinating bacterial stress responses against the unfavorable environmental and host conditions.

scholarly journals The Roles of Two Type VI Secretion Systems in Cronobacter sakazakii ATCC 12868

2018 ◽  
Vol 9 ◽  
Author(s):  
Min Wang ◽  
Hengchun Cao ◽  
Qian Wang ◽  
Tingting Xu ◽  
Xi Guo ◽  
...  
Keyword(s):  
Cronobacter Sakazakii ◽  
Secretion Systems ◽  
Type Vi Secretion

scholarly journals A family of T6SS antibacterial effectors related to L,D-transpeptidases targets the Peptidoglycan

2020 ◽  
Vol 2 (7A) ◽  
Author(s):  
Stephanie Sibinelli de Sousa ◽  
Julia Takuno Hespanhol ◽  
Bruno Matsuyama ◽  
Stephane Mesnage ◽  
Gianlucca Nicastro ◽  
...  
Keyword(s):  
Cell Envelope ◽  
Point Mutations ◽  
Time Lapse ◽  
Secretion Systems ◽  
Bacterial Antagonism ◽  
New Family ◽  
Type Vi Secretion ◽  
Altered Cell ◽  
Bacterial Effectors ◽  
Insight Into

Type VI secretion systems (T6SSs) are contractile nanomachines widely used by bacteria to intoxicate competitors. Salmonella Typhimurium encodes a T6SS within the Salmonella pathogenicity island 6 (SPI-6) that is used during competition against species of the gut microbiota. We characterized a new SPI-6 T6SS antibacterial effector named Tlde1 (type VI L,D-transpeptidase effector 1). Tlde1 is toxic in target-cell periplasm and its toxicity is neutralized by co-expression with immunity protein Tldi1 (type VI L,D-transpeptidase immunity 1). Time-lapse microscopy revealed that intoxicated cells display altered cell division and lose cell envelope integrity. Bioinformatics analysis showed that Tlde1 is evolutionarily related to L,D-transpeptidases. Point mutations on conserved histidine121 and cysteine131 residues eliminated toxicity. Co-incubation of purified recombinant Tlde1 and peptidoglycan tetrapeptides showed that Tlde1 displays both L,D-carboxypeptidase activity by cleaving GM-tetrapeptides between meso-diaminopimelic acid3 and D-alanine4, and L,D-transpeptidase exchange activity by replacing D-alanine4 for a non-canonical D-amino acid. Tlde1 constitutes a new family of T6SS effectors widespread in Proteobacteria. This work increases our knowledge about the bacterial effectors used in interbacterial competitions and provides molecular insight into a new mechanism of bacterial antagonism.

scholarly journals Two Type VI Secretion Systems of Enterobacter cloacae Are Required for Bacterial Competition, Cell Adherence, and Intestinal Colonization

2020 ◽  
Vol 11 ◽  
Author(s):  
Jorge Soria-Bustos ◽  
Miguel A. Ares ◽  
Carlos A. Gómez-Aldapa ◽  
Jorge A. González-y-Merchand ◽  
Jorge A. Girón ◽  
...  
Keyword(s):  
Enterobacter Cloacae ◽  
Intestinal Colonization ◽  
Secretion Systems ◽  
Cell Adherence ◽  
Bacterial Competition ◽  
Type Vi Secretion

scholarly journals Paraburkholderia phymatum STM815 σ54 Controls Utilization of Dicarboxylates, Motility, and T6SS-b Expression

Nitrogen ◽  
2020 ◽  
Vol 1 (2) ◽  
pp. 81-98
Author(s):  
Martina Lardi ◽  
Yilei Liu ◽  
Sebastian Hug ◽  
Samanta Bolzan de Campos ◽  
Leo Eberl ◽  
...  
Keyword(s):  
Wild Type Strain ◽  
Nitrogenase Activity ◽  
Secretion Systems ◽  
Free Living ◽  
Major Life ◽  
Life Styles ◽  
Type Vi Secretion ◽  
Flagellar Biosynthesis ◽  
Free Living Conditions

Rhizobia have two major life styles, one as free-living bacteria in the soil, and the other as bacteroids within the root/stem nodules of host legumes where they convert atmospheric nitrogen into ammonia. In the soil, rhizobia have to cope with changing and sometimes stressful environmental conditions, such as nitrogen limitation. In the beta-rhizobial strain Paraburkholderia phymatum STM815, the alternative sigma factor σ54 (or RpoN) has recently been shown to control nitrogenase activity during symbiosis with Phaseolus vulgaris. In this study, we determined P. phymatum’s σ54 regulon under nitrogen-limited free-living conditions. Among the genes significantly downregulated in the absence of σ54, we found a C4-dicarboxylate carrier protein (Bphy_0225), a flagellar biosynthesis cluster (Bphy_2926-64), and one of the two type VI secretion systems (T6SS-b) present in the P. phymatum STM815 genome (Bphy_5978-97). A defined σ54 mutant was unable to grow on C4 dicarboxylates as sole carbon source and was less motile compared to the wild-type strain. Both defects could be complemented by introducing rpoNin trans. Using promoter reporter gene fusions, we also confirmed that the expression of the T6SS-b cluster is regulated by σ54. Accordingly, we show that σ54 affects in vitro competitiveness of P. phymatum STM815 against Paraburkholderia diazotrophica.

scholarly journals Divergent Control of Two Type VI Secretion Systems by RpoN in Pseudomonas aeruginosa

PLoS ONE ◽  
2013 ◽  
Vol 8 (10) ◽  
pp. e76030 ◽  
Author(s):  
Thibault G. Sana ◽  
Chantal Soscia ◽  
Céline M. Tonglet ◽  
Steve Garvis ◽  
Sophie Bleves
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Secretion Systems ◽  
Type Vi Secretion

scholarly journals Type VI secretion systems in plant-associated bacteria

2017 ◽  
Vol 20 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Patricia Bernal ◽  
María A. Llamas ◽  
Alain Filloux
Keyword(s):  
Secretion Systems ◽  
Associated Bacteria ◽  
Type Vi Secretion

scholarly journals Baseplate assembly of phage Mu: Defining the conserved core components of contractile-tailed phages and related bacterial systems

2016 ◽  
Vol 113 (36) ◽  
pp. 10174-10179 ◽  
Author(s):  
Carina R. Büttner ◽  
Yingzhou Wu ◽  
Karen L. Maxwell ◽  
Alan R. Davidson
Keyword(s):  
Type Vi Secretion System ◽  
Secretion Systems ◽  
Phage Mu ◽  
Self Defense ◽  
Type Vi Secretion ◽  
Essential Components ◽  
Core Components ◽  
Contractile Tail ◽  
Equivalent Structure ◽  
Conserved Core

Contractile phage tails are powerful cell puncturing nanomachines that have been co-opted by bacteria for self-defense against both bacteria and eukaryotic cells. The tail of phage T4 has long served as the paradigm for understanding contractile tail-like systems despite its greater complexity compared with other contractile-tailed phages. Here, we present a detailed investigation of the assembly of a “simple” contractile-tailed phage baseplate, that of Escherichia coli phage Mu. By coexpressing various combinations of putative Mu baseplate proteins, we defined the required components of this baseplate and delineated its assembly pathway. We show that the Mu baseplate is constructed through the independent assembly of wedges that are organized around a central hub complex. The Mu wedges are comprised of only three protein subunits rather than the seven found in the equivalent structure in T4. Through extensive bioinformatic analyses, we found that homologs of the essential components of the Mu baseplate can be identified in the majority of contractile-tailed phages and prophages. No T4-like prophages were identified. The conserved simple baseplate components were also found in contractile tail-derived bacterial apparatuses, such as type VI secretion systems, Photorhabdus virulence cassettes, and R-type tailocins. Our work highlights the evolutionary connections and similarities in the biochemical behavior of phage Mu wedge components and the TssF and TssG proteins of the type VI secretion system. In addition, we demonstrate the importance of the Mu baseplate as a model system for understanding bacterial phage tail-derived systems.

scholarly journals The In Vitro and In Planta Interspecies Interactions Among Rice-Pathogenic Burkholderia Species

Plant Disease ◽  
2021 ◽  
Vol 105 (1) ◽  
pp. 134-143
Author(s):  
Namgyu Kim ◽  
Mohamed Mannaa ◽  
Juyun Kim ◽  
Ji-Eun Ra ◽  
Sang-Min Kim ◽  
...  
Keyword(s):  
Inhibitory Activity ◽  
Fluorescent Protein ◽  
Antagonistic Activity ◽  
In Vitro Assays ◽  
Interspecies Interactions ◽  
In Planta ◽  
Burkholderia Glumae ◽  
Burkholderia Species ◽  
Green Fluorescent

Burkholderia glumae, B. plantarii, and B. gladioli are responsible for serious diseases in rice crops and co-occurrence among them has been reported. In this study, in vitro assays revealed antagonistic activity among these organisms, with B. gladioli demonstrating strong inhibition of B. glumae and B. plantarii. Strains of B. glumae and B. plantarii that express green fluorescent protein were constructed and used for cocultivation assays with B. gladioli, which confirmed the strong inhibitory activity of B. gladioli. Cell-free supernatants from each species were tested against cultures of counterpart species to evaluate the potential to inhibit bacterial growth. To investigate the inhibitory activity of B. gladioli on B. glumae and B. plantarii in rice, rice plant assays were performed and quantitative PCR (qPCR) assays were developed for in planta bacterial quantification. The results indicated that coinoculation with B. gladioli leads to significantly reduced disease severity and colonization of rice tissues compared with single inoculation with B. glumae or B. plantarii. This study demonstrates the interactions among three rice-pathogenic Burkholderia species and strong antagonistic activity of B. gladioli in vitro and in planta. The qPCR assays developed here could be applied for accurate quantification of these organisms from in planta samples in future studies.

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