Identification of two genes,<i>cpsX</i>and<i>cpsY</i>, with putative regulatory function on capsule expression in group B streptococci

Koskiniemi, Satu; Sellin, Mats; Norgren, Mari

doi:10.1111/j.1574-695x.1998.tb01162.x

Cited by 25 publications

(3 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…CpsIaA has 44% similarity to LytR, a protein in Bacillus subtilis that is thought to act as a transcriptional regulator and has been suggested to perform the same role in GBS capsule expression (40). Disruption of lytR resulted in a 4-fold increase in transcription of lytABC, supporting a role for LytR as an attenuator of lyt operon transcription (20).…”

Section: Fig 2 Construction Of Nonpolar Deletion Mutants In Type Iamentioning

confidence: 92%

Functional Analysis in Type Ia Group B Streptococcusof a Cluster of Genes Involved in Extracellular Polysaccharide Production by Diverse Species of Streptococci

Cieslewicz¹,

Kasper²,

Wang³

et al. 2001

Journal of Biological Chemistry

145

144

View full text Add to dashboard Cite

Several species of streptococci produce extracellular polysaccharides in the form of secreted exopolysaccharides or cell-associated capsules. Although the biological properties and repeating unit structures of these polysaccharides are diverse, sequence analysis of the genes required for their production has revealed a surprising degree of conservation among five genes found in the capsule gene cluster of each of several polysaccharide-producing streptococci. To determine the function of these conserved genes, we characterized a series of isogenic mutants derived from a wild-type strain of type Ia group B Streptococcus by selectively inactivating each gene. Inactivation of cpsIaE resulted in an acapsular phenotype, consistent with previous work that identified the cpsIaE product as the glycosyltransferase that initiates synthesis of the polysaccharide repeating unit. Mutants in cpsIaA, cpsIaB, cpsIaC, or cpsIaD produced type Ia capsular polysaccharide, but in reduced amounts compared with the wild type. Analysis of the mutant polysaccharides and of capsule gene transcription in the mutant strains provided evidence that cpsIaA encodes a transcriptional activator that regulates expression of the capsule gene operon. Mutants in cpsIaC or cpsIaD produced polysaccharide of reduced molecular size but with an identical repeating unit structure as the wild-type strain. We conclude that CpsA to -D are not required for polysaccharide repeating unit biosynthesis but rather that they direct the coordinated polymerization and export of high molecular weight polysaccharide.

show abstract

Section: Fig 2 Construction Of Nonpolar Deletion Mutants In Type Iamentioning

confidence: 92%

Functional Analysis in Type Ia Group B Streptococcusof a Cluster of Genes Involved in Extracellular Polysaccharide Production by Diverse Species of Streptococci

Cieslewicz¹,

Kasper²,

Wang³

et al. 2001

Journal of Biological Chemistry

145

144

View full text Add to dashboard Cite

show abstract

“…CpsY shares homology (83% identity) with a LysR family transcriptional regulator of S. mutans (MetR), as well as to proteins in S. iniae (CpsY) and S. agalactiae (MtaR) that regulate methionine transport (25), amino acid metabolism (26), and resistance to neutrophilmediated killing and survival in vivo (27)(28)(29). This led us to hypothesize that CpsY functions as a transcriptional regulator of GAS metabolism required for survival in human host blood.…”

Section: Discussionmentioning

confidence: 99%

“…GAS CpsY displays 83% identity with MetR, a LysR family transcriptional regulator of Streptococcus mutans shown to activate transcription of genes involved in methionine biosynthesis (metE) and uptake (atmB) in a homocysteine-dependent manner (24). Homologs of CpsY found in Streptococcus iniae and Streptococcus agalactiae (MtaR) have been characterized as virulence determinants that regulate methionine transport (25), amino acid metabolism (26), and cell wall modifications necessary for resistance to neutrophilmediated killing and survival in vivo (27)(28)(29). Thus, CpsY appears to play a crucial role as a transcriptional regulator in the development of streptococcal invasive disease through the promotion of immune cell resistance and host niche adaptation.…”

mentioning

confidence: 99%

The Transcriptional Regulator CpsY Is Important for Innate Immune Evasion in Streptococcus pyogenes

et al. 2017

View full text Add to dashboard Cite

As an exclusively human pathogen, Streptococcus pyogenes (the group A streptococcus [GAS]) has specifically adapted to evade host innate immunity and survive in multiple tissue niches, including blood. GAS can overcome the metabolic constraints of the blood environment and expresses various immunomodulatory factors necessary for survival and immune cell resistance. Here we present our investigation of one such factor, the predicted LysR family transcriptional regulator CpsY. The encoding gene, cpsY, was initially identified as being required for GAS survival in a transposon-site hybridization (TraSH) screen in whole human blood. CpsY is homologous with transcriptional regulators of Streptococcus mutans (MetR), Streptococcus iniae (CpsY), and Streptococcus agalactiae (MtaR) that regulate methionine transport, amino acid metabolism, resistance to neutrophil-mediated killing, and survival in vivo. Our investigation indicated that CpsY is involved in GAS resistance to innate immune cells of its human host. However, GAS CpsY does not manifest the in vitro phenotypes of its homologs in other streptococcal species. GAS CpsY appears to regulate a small set of genes that is markedly different from the regulons of its homologs. The differential expression of these genes depends on the growth medium, and CpsY modestly influences their expression. The GAS CpsY regulon includes known virulence factors (mntE, speB, spd, nga [spn], prtS [SpyCEP], and sse) and cell surface-associated factors of GAS (emm1, mur1.2, sibA [cdhA], and M5005_Spy0500). Intriguingly, the loss of CpsY in GAS does not result in virulence defects in murine models of infection, suggesting that CpsY function in immune evasion is specific to the human host.

show abstract

Zebrafish as a model for zoonotic aquatic pathogens

Rowe¹,

Withey²,

Neely³

2014

Developmental & Comparative Immunology

View full text Add to dashboard Cite

Aquatic habitats harbor a multitude of bacterial species. Many of these bacteria can act as pathogens to aquatic species and/or non-aquatic organisms, including humans, that come into contact with contaminated water sources or colonized aquatic organisms. In many instances, the bacteria are not pathogenic to the aquatic species they colonize and are only considered pathogens when they come into contact with humans. There is a general lack of knowledge about how the environmental lifestyle of these pathogens allows them to persist, replicate and produce the necessary pathogenic mechanisms to successfully transmit to the human host and cause disease. Recently, the zebrafish infectious disease model has emerged as an ideal system for examining aquatic pathogens, both in the aquatic environment and during infection of the human host. This review will focus on how the zebrafish has been used successfully to analyze the pathogenesis of aquatic bacterial pathogens.

show abstract

Identification of two genes,cpsXandcpsY, with putative regulatory function on capsule expression in group B streptococci

Cited by 25 publications

References 26 publications

Functional Analysis in Type Ia Group B Streptococcusof a Cluster of Genes Involved in Extracellular Polysaccharide Production by Diverse Species of Streptococci

Functional Analysis in Type Ia Group B Streptococcusof a Cluster of Genes Involved in Extracellular Polysaccharide Production by Diverse Species of Streptococci

The Transcriptional Regulator CpsY Is Important for Innate Immune Evasion in Streptococcus pyogenes

Zebrafish as a model for zoonotic aquatic pathogens

Contact Info

Product

Resources

About