Serine/Threonine Phosphatase Stp1 Mediates Post-transcriptional Regulation of Hemolysin, Autolysis, and Virulence of Group B Streptococcus

Burnside, Kellie; Lembo, Annalisa; Harrell, Maria I.; Gurney, Michael A.; Xue, Liang; BinhTran, Nguyen Thao; Connelly, James E.; Jewell, Kelsea A.; Schmidt, Byron Z.; Reyes, Melissa de los; Tao, W. Andy; Doran, Kelly S.; Rajagopal, Lakshmi

doi:10.1074/jbc.m111.313486

Cited by 45 publications

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“…Phosphopeptide enrichment and MS. Total protein was isolated from the WT A909, the ⌬rgfCA d mutant, and ⌬rgfCA d /pRgfC complemented strain as described previously (35,36). Briefly, GBS were grown to an OD 600 of 0.6 in TSB.…”

Section: Methodsmentioning

confidence: 99%

“…The cells subsequently were resuspended in lysis buffer (50 mM Tris, pH 7.5, with the phosphatase inhibitors described above at a concentration of 5 mM) and disrupted using the FastPrep FP101 bead beater (Bio 101). The lysates were treated with DNase I and ultracentrifuged to pellet unlysed cells and cell debris at 25,000 ϫ g as described previously (35,36).The supernatant from each sample was normalized to contain equal amounts of protein. The proteins then were denatured and reduced in 4% SDS with 10 mM dithiothreitol (DTT) at 95°C for 5 min.…”

Section: Methodsmentioning

confidence: 99%

“…Data were searched using Proteome Discoverer software with the SEQUEST algorithm using a 10-ppm precursor mass tolerance and a 0.6-Da MS/MS mass tolerance. The searches included variable modifications on cysteine residues (ϩ57.021 or ϩ79.966), methionine residues (ϩ15.995), and aspartate, serine, threonine, and tyrosine residues (ϩ79.966) to identify phosphorylation as described previously (35,36,38). Spectra were searched against the GBS A909 genome database (accession number NC_007432) with a 1% false discovery rate (FDR) based on a reverse decoy database search.…”

Section: Methodsmentioning

confidence: 99%

“…S1 in the supplemental material). We next compared the virulence potential of the ⌬rgfCA d mutant to that of WT A909 using the neonatal rat sepsis model of infection described previously (27,31,35). Interestingly, the 50% moribund dose (MD 50 ; previously known as LD 50 ) estimates of the ⌬rgfCA d mutant were 10-fold lower than those for WT A909 (Table 1) (P ϭ 0.012).…”

Section: Gbs Deficient In Rgfc Expression Exhibit Increased Virulencementioning

confidence: 99%

“…To determine if the absence of RgfC affected gene expression in GBS A909, we performed microarray analysis using methods described previously (12,35; also see Materials and Methods). The results shown in Table S2 in the supplemental material indicate that 101 genes showed increased expression, and 115 (excluding rgfC-rgfA) genes showed decreased expression in the A909 ⌬rgfCA d mutant.…”

Section: Fig 1 Sequence Alignment and Open Reading Frame Of The Tcs Rmentioning

confidence: 99%

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The Sensor Histidine Kinase RgfC Affects Group B Streptococcal Virulence Factor Expression Independent of Its Response Regulator RgfA

et al. 2015

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Group B streptococci (GBS; Streptococcus agalactiae) are beta-hemolytic, Gram-positive bacteria that are common asymptomatic colonizers of healthy adults. However, these opportunistic bacteria also cause invasive infections in human newborns and in certain adult populations. To adapt to the various environments encountered during its disease cycle, GBS encodes a number of two-component signaling systems. Previous studies have indicated that the TCS comprising the sensor histidine kinase RgfC and the response regulator RgfA mediate GBS binding to extracellular matrix components, such as fibrinogen. However, in certain GBS clinical isolates, a point mutation in rgfA results in premature truncation of the response regulator. The truncated RgfA protein lacks the C-terminal DNA binding domain necessary for promoter binding and gene regulation. Here, we show that deletion of rgfC in GBS strains lacking a functional RgfA increased systemic infection. Furthermore, infection with the rgfC mutant increased induction of proinflammatory signaling pathways in vivo. Phosphoproteomic analysis revealed that 19 phosphopeptides corresponding to 12 proteins were differentially phosphorylated at aspartate, cysteine, serine, threonine, or tyrosine residues in the rgfC mutant. This included aspartate phosphorylation of a tyrosine kinase, CpsD, and a transcriptional regulator. Consistent with this observation, microarray analysis of the rgfC mutant indicated that >200 genes showed altered expression compared to the isogenic wild-type strain and included transcriptional regulators, transporters, and genes previously associated with GBS pathogenesis. Our observations suggest that in the absence of RgfA, nonspecific RgfC signaling affects the expression of virulence factors and GBS pathogenesis.A ll living organisms sense and adapt to dynamic changes in their environment using signaling systems. Signaling in prokaryotic organisms is achieved primarily by two-component signaling systems (TCS) that regulate gene expression in response to environmental signals (1-5). A typical two-component system comprises a membrane-associated sensor histidine kinase that responds to an environmental signal and phosphorylates its cognate DNA binding response regulator at an aspartate residue. Phosphorylation often alters the affinity of the response regulator to its target promoters, regulating gene expression.Group B streptococci (GBS) or Streptococcus agalactiae strains are a common cause of bacterial infections in human newborns and are emerging pathogens of adult humans (6). These bacteria reside as commensal organisms in the lower gastrointestinal and genital tracts of healthy adult women. Human neonates are at risk for GBS infections due to ascending infection from the lower genital tract or from aspiration of contaminated amniotic/vaginal fluids during birth. GBS can disseminate into multiple neonatal organs, causing pneumonia, sepsis, and meningitis (for reviews, see references 6-8). Thus, GBS has to efficiently adapt to the changing environmental...

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Gbs Deficient In Rgfc Expression Exhibit Increased Virulencementioning

confidence: 99%

Section: Fig 1 Sequence Alignment and Open Reading Frame Of The Tcs Rmentioning

confidence: 99%

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The Sensor Histidine Kinase RgfC Affects Group B Streptococcal Virulence Factor Expression Independent of Its Response Regulator RgfA

et al. 2015

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Importance of protein Ser/Thr/Tyr phosphorylation for bacterial pathogenesis

et al. 2020

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Protein phosphorylation regulates a large variety of biological processes in all living cells. In pathogenic bacteria, the study of serine, threonine, and tyrosine (Ser/Thr/Tyr) phosphorylation has shed light on the course of infectious diseases, from adherence to host cells to pathogen virulence, replication, and persistence. Mass spectrometry (MS)-based phosphoproteomics has provided global maps of Ser/Thr/Tyr phosphosites in bacterial pathogens. Despite recent developments, a quantitative and dynamic view of phosphorylation events that occur during bacterial pathogenesis is currently lacking. Temporal, spatial, and subpopulation resolution of phosphorylation data is required to identify key regulatory nodes underlying bacterial pathogenesis. Herein, we discuss how technological improvements in sample handling, MS instrumentation, data processing, and machine learning should improve bacterial phosphoproteomic datasets and the information extracted from them. Such information is expected to significantly extend the current knowledge of Ser/ Thr/Tyr phosphorylation in pathogenic bacteria and should ultimately contribute to the design of novel strategies to combat bacterial infections.

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Common Regulators of Virulence in Streptococci

Patenge

Fiedler

Kreikemeyer

2012

Host-Pathogen Interactions in Streptococcal Diseases

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Streptococcal species are a diverse group of bacteria which can be found in animals and humans. Their interactions with host organisms can vary from commensal to pathogenic. Many of the pathogenic species are causative agents of severe, invasive infections in their hosts, accounting for a high burden of morbidity and mortality, associated with high economic costs in industry and health care. Among them, Streptococcus pyogenes, Streptococcus agalactiae, Streptococcus pneumoniae, and Streptococcus suis are discussed here. An environmentally stimulated and tightly controlled expression of their virulence factors is of utmost importance for their pathogenic potential. Thus, the most universal and widespread regulators from the classes of stand-alone transcriptional regulators, two-component signal transduction systems (TCS), eukaryotic-like serine/threonine kinases, and small noncoding RNAs are the topic of this chapter. The regulatory levels are reviewed with respect to function, activity, and their role in pathogenesis. Understanding of and interfering with transcriptional regulation mechanisms and networks is a promising basis for the development of novel anti-infective therapies.

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Serine/Threonine Phosphatase Stp1 Mediates Post-transcriptional Regulation of Hemolysin, Autolysis, and Virulence of Group B Streptococcus

Cited by 45 publications

References 95 publications

The Sensor Histidine Kinase RgfC Affects Group B Streptococcal Virulence Factor Expression Independent of Its Response Regulator RgfA

The Sensor Histidine Kinase RgfC Affects Group B Streptococcal Virulence Factor Expression Independent of Its Response Regulator RgfA

Importance of protein Ser/Thr/Tyr phosphorylation for bacterial pathogenesis

Common Regulators of Virulence in Streptococci

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