Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The . gov means it’s official. Federal government websites often end in . gov or . mil. Before sharing sensitive information, make sure you’re on a federal government site VSports app下载. .

Https

The site is secure. The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely V体育官网. .

. 2006 Nov;48(2):283-92.
doi: 10.1111/j.1574-695X.2006.00150.x. Epub 2006 Sep 25.

Inactivation of the group A Streptococcus regulator srv results in chromosome wide reduction of transcript levels, and changes in extracellular levels of Sic and SpeB

Sean D Reid  1 , Michael S Chaussee, Christopher D Doern, Michelle A Chaussee, Alison G Montgomery, Daniel E Sturdevant, James M Musser
Affiliations

Inactivation of the group A Streptococcus regulator srv results in chromosome wide reduction of transcript levels, and changes in extracellular levels of Sic and SpeB (VSports)

Sean D Reid et al. FEMS Immunol Med Microbiol. 2006 Nov.

"V体育官网" Abstract

Group A Streptococcus is characterized by the ability to cause a diverse number of human infections including pharyngitis, necrotizing fasciitis, toxic shock syndrome, and acute rheumatic fever, yet the regulation of streptococcal genes involved in disease processes and survival in the host is not completely understood. Genome scale analysis has revealed a complex regulatory network including 13 two-component regulatory systems and more than 100 additional putative regulators, the majority of which remain uncharacterized VSports手机版. Among these is the streptococcal regulator of virulence, Srv, the first Group A Streptococcus member of the Crp/Fnr family of transcriptional regulators. Previous work demonstrated that the loss of srv resulted in a significant decrease in Group A Streptococcus virulence. To begin to define the gene products influenced by Srv, we combined microarray and two-dimensional gel electrophoresis analysis. Loss of srv results in a chromosome wide reduction of gene transcription and changes in the production of the extracellular virulence factors Sic (streptococcal inhibitor of complement) and SpeB (cysteine proteinase). Sic levels are reduced in the srv mutant, whereas the extracellular concentration and activity of SpeB is increased. These data link Srv to the increasingly complex GAS regulatory network. .

PubMed Disclaimer

Figures

Fig. 1
Fig. 1
Correlation of DNA microarray and real-time reverse transcriptase-PCR analysis. The fold changes in transcript of MGAS5005Δsrv relative to MGAS5005 obtained by microarray and real-time reverse transcriptase-PCR were log-transformed and plotted against each other to measure the correlation. The transcription of five genes was compared. Two genes were analyzed from RNA isolated at A600 nm = 0.4, while three separate genes were analyzed from RNA isolated at A600 nm = 0.6.
Fig. 2
Fig. 2
Two-dimensional gel electrophoresis separation of culture supernatant proteins from MGAS5005 (a, c) and the isogenic mutant lacking srv, MGAS5005Δsrv (b, d). Circled proteins are Sic (a, b) and the zymogen form of SpeB (c, d). There is a marked reduction in the amount of Sic present in the supernatant of MGAS5005Δsrv (b) and an increase in the amount of SpeB present (d) compared to the parental strain (c).
Fig. 3
Fig. 3
Casein agar assay for SpeB proteolytic activity. MGAS5005 (a) and MGAS5005Δsrv (b) were stab inoculated into agar plates containing skim milk and incubated for 18 h anaerobically. Proteinase activity is manifest as a zone of translucence surrounding the stab sites. There is a marked increase in the amount of SpeB proteolysis exhibited by MGAS5005Δsrv compared to MGAS5005.
Fig. 4
Fig. 4
Immunoblot analysis of culture supernatant fluids isolated from MGAS5005 and MGAS5005Δsrv during the exponential phase of growth. Antisera to SpeB was used to analyze 20 μg of protein isolated from MGAS5005 (lanes 1, 3) and MGAS5005Δsrv (lanes 2, 4) after 2 (lanes 1, 2) and 8 h (lanes 3, 4) of growth. 1.5 μg of purified SpeB was used as a control (lane 5).
See this image and copyright information in PMC

References

    1. Akesson P, Sjoholm AG, Bjorck L. Protein SIC, a novel extracellular protein of Streptococcus pyogenes interfering with complement function. J Biol Chem. 1996;271:1081–1088. - PubMed
    1. Banks DJ, Porcella SF, Barbian KD, Beres SB, Philips LE, Voyich JM, DeLeo FR, Martin JM, Somerville GA, Musser JM. Progress toward characterization of the group A Streptococcus metagenome: complete genome sequence of a macrolide-resistant serotype M6 strain. J Infect Dis. 2004;190:727–738. - PubMed
    1. Beres SB, Sylva GL, Barbian KD, et al. Genome sequence of a serotype M3 strain of group A Streptococcus: phage-encoded toxins, the high-virulence phenotype, and clone emergence. Proc Natl Acad Sci USA. 2002;99:10078–10083. - PMC - PubMed
    1. Bessen D, Jones KF, Fischetti VA. Evidence for two distinct classes of streptococcal M protein and their relationship to rheumatic fever. J Exp Med. 1989;169:269–283. - PMC - PubMed
    1. Bessen DE, Sotir CM, Readdy TL, Hollingshead SK. Genetic correlates of throat and skin isolates of group A streptococci. J Infect Dis. 1996;173:896–900. - "V体育安卓版" PubMed

Publication types

"VSports手机版" MeSH terms