Neisseria meningitidis Polynucleotide Phosphorylase Affects Aggregation, Adhesion, and Virulence

Jakob, Engman; Negrea, Aurel; Spilimbergo, Sara; Geörg, Miriam; Eriksson, Jens; Eriksson, Olaspers Sara; Kuwae, Asaomi; Sjölinder, Hong; Jonsson, Ann‐Beth

doi:10.1128/iai.01463-15

Cited by 20 publications

(14 citation statements)

References 64 publications

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“…Depletion of RNase E from the cell reduces T3SS gene expression and protein abundance. While further investigation is needed to fully elucidate the mechanism by which RNase E controls T3SS gene expression, our data support recent findings that RNases are important players in the control of virulence gene expression in a variety of pathogenic bacteria (23,(42)(43)(44)(45)(46).…”

Section: Discussionsupporting

confidence: 87%

RNase E Promotes Expression of Type III Secretion System Genes in Pseudomonas aeruginosa

2019

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Pseudomonas aeruginosa is an important opportunistic pathogen that employs a type III secretion system (T3SS) to inject effector proteins into host cells. Using a protein depletion system, we show that the endoribonuclease RNase E positively regulates expression of the T3SS genes. We also present evidence that RNase E antagonizes the expression of genes of the type VI secretion system and limits biofilm production in P. aeruginosa. Thus, RNase E, which is thought to be the principal endoribonuclease involved in the initiation of RNA degradation in P. aeruginosa, plays a key role in controlling the production of factors involved in both acute and chronic stages of infection. Although the posttranscriptional regulator RsmA is also known to positively regulate expression of the T3SS genes, we find that RNase E does not appreciably influence the abundance of RsmA in P. aeruginosa. Moreover, we show that RNase E still exerts its effects on T3SS gene expression in cells lacking all four of the key small regulatory RNAs that function by sequestering RsmA. IMPORTANCE The type III secretion system (T3SS) is a protein complex produced by many Gram-negative pathogens. It is capable of injecting effector proteins into host cells that can manipulate cell metabolism and have toxic effects. Understanding how the T3SS is regulated is important in understanding the pathogenesis of bacteria with such systems. Here, we show that RNase E, which is typically thought of as a global regulator of RNA stability, plays a role in regulating the T3SS in Pseudomonas aeruginosa. Depleting RNase E results in the loss of T3SS gene expression as well as a concomitant increase in biofilm formation. These observations are reminiscent of the phenotypes associated with the loss of activity of the posttranscriptional regulator RsmA. However, RNase E-mediated regulation of these systems does not involve changes in the abundance of RsmA and is independent of the known small regulatory RNAs that modulate RsmA activity.

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Section: Discussionsupporting

confidence: 87%

RNase E Promotes Expression of Type III Secretion System Genes in Pseudomonas aeruginosa

2019

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“…However, no significant changes were observed in expression of the transcriptional regulators misR or pnp [8, 29]. Additionally, no significant changes were observed in the genes pglC , pglI , pglB2 , pglH and pglL , encoding for pilus posttranslational modification enzymes [30], (Fig 3A).…”

Section: Resultsmentioning

confidence: 99%

Host cell-derived lactate functions as an effector molecule in Neisseria meningitidis microcolony dispersal

et al. 2017

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The development of meningococcal disease, caused by the human pathogen Neisseria meningitidis, is preceded by the colonization of the epithelial layer in the nasopharynx. After initial adhesion to host cells meningococci form aggregates, through pilus-pilus interactions, termed microcolonies from which the bacteria later detach. Dispersal from microcolonies enables access to new colonization sites and facilitates the crossing of the cell barrier; however, this process is poorly understood. In this study, we used live-cell imaging to investigate the process of N. meningitidis microcolony dispersal. We show that direct contact with host cells is not required for microcolony dispersal, instead accumulation of a host-derived effector molecule induces microcolony dispersal. By using a host-cell free approach, we demonstrated that lactate, secreted from host cells, initiate rapid dispersal of microcolonies. Interestingly, metabolic utilization of lactate by the bacteria was not required for induction of dispersal, suggesting that lactate plays a role as a signaling molecule. Furthermore, Neisseria gonorrhoeae microcolony dispersal could also be induced by lactate. These findings reveal a role of host-secreted lactate in microcolony dispersal and virulence of pathogenic Neisseria.

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“…For instance, PNPase inactivation affects E. coli virulence, particularly increasing Tir protein content and transcription of Type III secretion system components, including intimin, Tir and EspB in E. coli O157:H7 84 . PNPase also negatively affects N. meningitidis aggregation and adhesion mediated by Type IV pili 85 , as well as transcription of the genes encoding Type IV pili and the Type III secretion system in P. aeruginosa 86 . In addition to the control of yeeJ , it is possible that PNPase also regulates the expression of other surface factors in E. coli , although this remains to be demonstrated.…”

Section: Discussionmentioning

confidence: 99%

YeeJ is an inverse autotransporter from Escherichia coli that binds to peptidoglycan and promotes biofilm formation

Martínez-Gil

Goh

Rackaityte

et al. 2017

Sci Rep

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Escherichia coli is a commensal or pathogenic bacterium that can survive in diverse environments. Adhesion to surfaces is essential for E. coli colonization, and thus it is important to understand the molecular mechanisms that promote this process in different niches. Autotransporter proteins are a class of cell-surface factor used by E. coli for adherence. Here we characterized the regulation and function of YeeJ, a poorly studied but widespread representative from an emerging class of autotransporter proteins, the inverse autotransporters (IAT). We showed that the yeeJ gene is present in ~40% of 96 completely sequenced E. coli genomes and that YeeJ exists as two length variants, albeit with no detectable functional differences. We demonstrated that YeeJ promotes biofilm formation in different settings through exposition at the cell-surface. We also showed that YeeJ contains a LysM domain that interacts with peptidoglycan and thus assists its localization into the outer membrane. Additionally, we identified the Polynucleotide Phosphorylase PNPase as a repressor of yeeJ transcription. Overall, our work provides new insight into YeeJ as a member of the recently defined IAT class, and contributes to our understanding of how commensal and pathogenic E. coli colonise their environments.

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Neisseria meningitidis Polynucleotide Phosphorylase Affects Aggregation, Adhesion, and Virulence

Cited by 20 publications

References 64 publications

RNase E Promotes Expression of Type III Secretion System Genes in Pseudomonas aeruginosa

RNase E Promotes Expression of Type III Secretion System Genes in Pseudomonas aeruginosa

Host cell-derived lactate functions as an effector molecule in Neisseria meningitidis microcolony dispersal

YeeJ is an inverse autotransporter from Escherichia coli that binds to peptidoglycan and promotes biofilm formation

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