scholarly journals Genome‐wide analysis of in vivo CcpA binding with and without its key co‐factor HPr in the major human pathogen group A Streptococcus

2020 ◽  
Author(s):  
Sruti DebRoy ◽  
Victor Aliaga‐Tobar ◽  
Gabriel Galvez ◽  
Srishtee Arora ◽  
Xiaowen Liang ◽  
...  
PLoS ONE ◽  
2009 ◽  
Vol 4 (11) ◽  
pp. e7668 ◽  
Author(s):  
Nataly Perez ◽  
Jeanette Treviño ◽  
Zhuyun Liu ◽  
Siu Chun Michael Ho ◽  
Paul Babitzke ◽  
...  

2020 ◽  
Author(s):  
Sruti DebRoy ◽  
Victor Aliaga Tobar ◽  
Gabriel Galvez ◽  
Srishtee Arora ◽  
Xiaowen Liang ◽  
...  

SummaryCatabolite control protein A (CcpA) is a master regulator of carbon source utilization and contributes to the virulence of numerous medically important Gram-positive bacteria. Most functional assessments of CcpA, including interaction with its key co-factor HPr, have been performed in non-pathogenic bacteria. In this study we aimed to identify the in vivo DNA binding profile of CcpA and assess the extent to which HPr is required for CcpA-mediated regulation and DNA binding in the major human pathogen group A Streptococcus (GAS). Using a combination RNAseq/ChIPseq approach, we found that CcpA affects transcript levels of 514 of 1667 GAS genes (31%) whereas direct DNA binding was identified for 105 GAS genes. Three of the directly regulated genes encode the key GAS virulence factors Streptolysin S, PrtS (IL-8 degrading proteinase), and SpeB (cysteine protease). Mutating CcpA Val301 to Ala (strain 2221-CcpA-V301A) abolished interaction between CcpA and HPr and impacted the transcript levels of 205 genes (40%) in the total CcpA regulon. By ChIPseq analysis, CcpAV301A bound to DNA from 74% of genes bound by wild-type CcpA, but generally with lower affinity. These data delineate the direct CcpA regulon and clarify the HPr-dependent and independent activities of CcpA in a key pathogenic bacterium.Data sharing and data availabilityThe data that support the findings of this study are available from the corresponding author upon reasonable request.


2018 ◽  
Vol 86 (5) ◽  
Author(s):  
Nishanth Makthal ◽  
Hackwon Do ◽  
Arica R. VanderWal ◽  
Randall J. Olsen ◽  
James M. Musser ◽  
...  

ABSTRACTBacterial virulence factor production is a highly coordinated process. The temporal pattern of bacterial gene expression varies in different host anatomic sites to overcome niche-specific challenges. The human pathogen group A streptococcus (GAS) produces a potent secreted protease, SpeB, that is crucial for pathogenesis. Recently, we discovered that a quorum sensing pathway comprised of a leaderless short peptide, SpeB-inducing peptide (SIP), and a cytosolic global regulator, RopB, controlsspeBexpression in concert with bacterial population density. The SIP signaling pathway is activein vivoand contributes significantly to GAS invasive infections. In the current study, we investigated the role of the SIP signaling pathway in GAS-host interactions during oropharyngeal colonization. The SIP signaling pathway is functional during growthex vivoin human saliva. SIP-mediatedspeBexpression plays a crucial role in GAS colonization of the mouse oropharynx. GAS employs a distinct pattern of SpeB production during growthex vivoin saliva that includes a transient burst ofspeBexpression during early stages of growth coupled with sustained levels of secreted SpeB protein. SpeB production aids GAS survival by degrading LL37, an abundant human antimicrobial peptide. We found that SIP signaling occurs during growth in human bloodex vivo. Moreover, the SIP signaling pathway is critical for GAS survival in blood. SIP-dependentspeBregulation is functional in strains of diverseemmtypes, indicating that SIP signaling is a conserved virulence regulatory mechanism. Our discoveries have implications for future translational studies.


2014 ◽  
Vol 82 (7) ◽  
pp. 2890-2901 ◽  
Author(s):  
Marilena Gallotta ◽  
Giovanni Gancitano ◽  
Giampiero Pietrocola ◽  
Marirosa Mora ◽  
Alfredo Pezzicoli ◽  
...  

ABSTRACTGroup A streptococcus (GAS) is a human pathogen causing a wide repertoire of mild and severe diseases for which no vaccine is yet available. We recently reported the identification of three protein antigens that in combination conferred wide protection against GAS infection in mice. Here we focused our attention on the characterization of one of these three antigens, Spy0269, a highly conserved, surface-exposed, and immunogenic protein of unknown function. Deletion of thespy0269gene in a GAS M1 isolate resulted in very long bacterial chains, which is indicative of an impaired capacity of the knockout mutant to properly divide. Confocal microscopy and immunoprecipitation experiments demonstrated that the protein was mainly localized at the cell septum and could interactin vitrowith the cell division protein FtsZ, leading us to hypothesize that Spy0269 is a member of the GAS divisome machinery. Predicted structural domains and sequence homologies with known streptococcal adhesins suggested that this antigen could also play a role in mediating GAS interaction with host cells. This hypothesis was confirmed by showing that recombinant Spy0269 could bind to mammalian epithelial cellsin vitroand thatLactococcus lactisexpressing Spy0269 on its cell surface could adhere to mammalian cellsin vitroand to mice nasal mucosain vivo. On the basis of these data, we believe that Spy0269 is involved both in bacterial cell division and in adhesion to host cells and we propose to rename this multifunctional moonlighting protein as SpyAD (StreptococcuspyogenesAdhesion andDivision protein).


2013 ◽  
Vol 42 (5) ◽  
pp. 2893-2905 ◽  
Author(s):  
Chunjing Bian ◽  
Xiaochun Yu

Abstract Ten-eleven translocation (TET) family enzymes convert 5-methylcytosine to 5-hydroxylmethylcytosine. However, the molecular mechanism that regulates this biological process is not clear. Here, we show the evidence that PGC7 (also known as Dppa3 or Stella) interacts with TET2 and TET3 both in vitro and in vivo to suppress the enzymatic activity of TET2 and TET3. Moreover, lacking PGC7 induces the loss of DNA methylation at imprinting loci. Genome-wide analysis of PGC7 reveals a consensus DNA motif that is recognized by PGC7. The CpG islands surrounding the PGC7-binding motifs are hypermethylated. Taken together, our study demonstrates a molecular mechanism by which PGC7 protects DNA methylation from TET family enzyme-dependent oxidation.


2003 ◽  
Vol 51 (1) ◽  
pp. 123-134 ◽  
Author(s):  
Ramy K. Aziz ◽  
Michael J. Pabst ◽  
Arthur Jeng ◽  
Rita Kansal ◽  
Donald. E. Low ◽  
...  

2019 ◽  
Vol 216 (7) ◽  
pp. 1615-1629 ◽  
Author(s):  
Andreas Naegeli ◽  
Eleni Bratanis ◽  
Christofer Karlsson ◽  
Oonagh Shannon ◽  
Raja Kalluru ◽  
...  

Streptococcus pyogenes (Group A streptococcus; GAS) is a human pathogen causing diseases from uncomplicated tonsillitis to life-threatening invasive infections. GAS secretes EndoS, an endoglycosidase that specifically cleaves the conserved N-glycan on IgG antibodies. In vitro, removal of this glycan impairs IgG effector functions, but its relevance to GAS infection in vivo is unclear. Using targeted mass spectrometry, we characterized the effects of EndoS on host IgG glycosylation during the course of infections in humans. Substantial IgG glycan hydrolysis occurred at the site of infection and systemically in the severe cases. We demonstrated decreased resistance to phagocytic killing of GAS lacking EndoS in vitro and decreased virulence in a mouse model of invasive infection. This is the first described example of specific bacterial IgG glycan hydrolysis during infection and thereby verifies the hypothesis that EndoS modifies antibodies in vivo. This mechanisms of immune evasion could have implications for treatment of severe GAS infections and for future efforts at vaccine development.


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