Abstract:
:Cnm is a surface-associated protein present in a subset of Streptococcus mutans strains that mediates binding to extracellular matrices, intracellular invasion, and virulence. Here, we showed that cnm transcription is controlled by the global regulators CovR and VicRKX. In silico analysis identified multiple putative CovR- and VicR-binding motifs in the regulatory region of cnm as well as in the downstream gene pgfS, which is associated with the posttranslational modification of Cnm. Electrophoretic mobility shift assays revealed that CovR and VicR specifically and independently bind to the cnm and pgfS promoter regions. Quantitative real-time PCR and Western blot analyses of ΔcovR and ΔvicK strains as well as of a strain overexpressing vicRKX revealed that CovR functions as a positive regulator of cnm, whereas VicRKX acts as a negative regulator. In agreement with the role of VicRKX as a repressor, the ΔvicK strain showed enhanced binding to collagen and laminin and higher intracellular invasion rates. Overexpression of vicRKX was associated with decreased rates of intracellular invasion but did not affect collagen or lamin binding activities, suggesting that this system controls additional genes involved in binding to these extracellular matrix proteins. As expected, based on the role of CovR in cnm regulation, the ΔcovR strain showed decreased intracellular invasion rates, but, unexpectedly collagen and laminin binding activities were increased in this mutant strain. Collectively, the results presented here expand the repertoire of virulence-related genes regulated by CovR and VicRKX to include the core gene pgfS and the noncore gene cnmIMPORTANCEStreptococcus mutans is a major pathogen associated with dental caries and also implicated in systemic infections, in particular, infective endocarditis. The Cnm adhesin of S. mutans is an important virulence factor associated with systemic infections and caries severity. Despite its role in virulence, the regulatory mechanisms governing cnm expression are poorly understood. Here, we describe the identification of two independent regulatory systems controlling the transcription of cnm and the downstream pgfS-pgfM1-pgfE-pgfM2 operon. A better understanding of the mechanisms controlling expression of virulence factors like Cnm can facilitate the development of new strategies to treat bacterial infections.
journal_name
J Bacterioljournal_title
Journal of bacteriologyauthors
Araújo Alves L,Ganguly T,Mattos-Graner RO,Kajfasz J,Harth-Chu EN,Lemos JA,Abranches Jdoi
10.1128/JB.00141-18subject
Has Abstractpub_date
2018-11-06 00:00:00issue
23eissn
0021-9193issn
1098-5530pii
JB.00141-18journal_volume
200pub_type
杂志文章abstract::Fowler, Audree V. (University of California, Los Angeles), and Irving Zabin. Effects of dimethylsulfoxide on the lactose operon in Escherichia coli. J. Bacteriol. 92:353-357. 1966.-Dimethylsulfoxide (DMSO) at a concentration of 5% (v/v) in the culture medium inhibits the growth of Escherichia coli to only a slight ext...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.92.2.353-357.1966
更新日期:1966-08-01 00:00:00
abstract::Efficient hydrolysis of native poly(3-hydroxybutyrate) (nPHB) granules in vitro by soluble PHB depolymerase of Rhodospirillum rubrum requires pretreatment of nPHB with an activator compound present in R. rubrum cells (J. M. Merrick and M. Doudoroff, J. Bacteriol. 88:60-71, 1964). Edman sequencing of the purified activ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.186.8.2466-2475.2004
更新日期:2004-04-01 00:00:00
abstract::Accumulation of l-alpha-glycerophosphate, in cells of Bacillus subtilis mutants lacking the nicotinamide adenine dinucleotide-independent glycerophosphate dehydrogenase activity, suppresses both growth and sporulation. After growth has stopped, the cells slowly develop one and later more asymmetric septa that are thic...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.113.2.1034-1045.1973
更新日期:1973-02-01 00:00:00
abstract::A novel genetic scheme allowed us to isolate extragenic suppressor mutations that restored mutant OmpF assembly. One group of these mutations, termed asmB for assembly suppressor mutation B, permitted mutant OmpF assembly in a non-allele-specific manner. Genetic mapping analyses placed the asmB mutations at the 2-min ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.178.17.5138-5143.1996
更新日期:1996-09-01 00:00:00
abstract::O antigen is the major cell surface antigen of gram-negative bacteria, and the genes responsible for its synthesis are located in a single gene cluster. The wzx (rbfX) gene, which is characteristic of the major class of O-antigen gene clusters, encodes a hydrophobic protein with 12 potential transmembrane segments. We...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.178.7.2102-2107.1996
更新日期:1996-04-01 00:00:00
abstract::The glucosamine-1-phosphate acetyltransferase activity but not the uridyltransferase activity of the bifunctional GlmU enzyme from Escherichia coli was lost when GlmU was stored in the absence of beta-mercaptoethanol or incubated with thiol-specific reagents. The enzyme was protected from inactivation in the presence ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.180.18.4799-4803.1998
更新日期:1998-09-01 00:00:00
abstract::The method of shuttle mutagenesis has been extended to Neisseria gonorrhoeae. We have constructed a defective mini-Tn3 derivative that encodes chloramphenicol resistance in both N. gonorrhoeae and Escherichia coli and selected for mutations in the chloramphenicol resistance gene that express higher levels of antibioti...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.172.1.40-46.1990
更新日期:1990-01-01 00:00:00
abstract::Glycosylation is a common modulation of protein function in eukaryotes and is biologically important. However, in bacteria protein glycosylation is rare, and relatively few bacterial glycoproteins are known. In Escherichia coli only two glycoproteins have been described to date. Here we introduce a novel member to thi...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.188.5.1798-1807.2006
更新日期:2006-03-01 00:00:00
abstract::Strain IMCC3088, cultivated from the Yellow Sea, is a novel isolate belonging to the OM60/NOR5 clade and is closely related to clone OM241, Congregibacter litoralis, and strain HTCC2080. Here, the genome sequence of strain IMCC3088 is presented, showing the absence of photosynthetic gene clusters and the presence of p...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.05111-11
更新日期:2011-07-01 00:00:00
abstract::Dormant spores of Bacillus subtilis exhibit two prominent X-ray scattering peaks. These peaks persisted in spores lacking most alpha/beta-type small, acid-soluble protein or the CotE protein responsible for assembly of much spore coat protein, but they were absent from spores of strains lacking the late sporulation-sp...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01200-09
更新日期:2009-12-01 00:00:00
abstract::We describe the identification and characterization of two genes and their gene products responsible for determining receptor binding and pilus length in type 1-piliated Escherichia coli. One gene, pilE, conferred the ability of piliated cells to agglutinate guinea pig erythrocytes. The other gene, pilF, determined pi...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.169.2.640-645.1987
更新日期:1987-02-01 00:00:00
abstract:UNLABELLED:Multiple essential small GTPases are involved in the assembly of the ribosome or in the control of its activity. Among them, ObgE (CgtA) has been shown recently to act as a ribosome antiassociation factor that binds to ppGpp, a regulator whose best-known target is RNA polymerase. The present study was aimed ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00159-16
更新日期:2016-06-13 00:00:00
abstract::Production of Bacillus subtilis exoproteases is positively regulated by the DegS-DegU two-component regulatory system and other regulatory factors including DegR and ProB. It was shown that the expression of degR was virtually abolished in a sigD mutant and that the transcriptional initiation site in vivo is preceded ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.178.1.216-222.1996
更新日期:1996-01-01 00:00:00
abstract::The Shiga toxin operon (stx) is composed of two genes for the A and B subunits, which are transcribed from a promoter 5' to the stxA gene. The 1A:5B subunit stoichiometry of the holotoxin suggests that the stxA and stxB genes are differentially regulated. In a previous study, we demonstrated the existence of a second ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.175.3.597-603.1993
更新日期:1993-02-01 00:00:00
abstract::Campylobacter jejuni, a spiral-shaped gram-negative bacterium, is a leading bacterial cause of human food-borne illness. Acute disease is associated with C. jejuni invasion of the intestinal epithelium. Further, maximal host cell invasion requires the secretion of proteins termed Campylobacter invasion antigens (Cia)....
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01736-07
更新日期:2008-04-01 00:00:00
abstract::The trfA gene of the broad-host-range plasmid RK2 is essential for initiation of plasmid replication. Two related TrfA proteins of 43 and 32 kilodaltons (kDa) are produced by independent translation initiation at two start codons within the trfA open reading frame. These proteins were o overproduced in Escherichia col...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.172.7.3849-3858.1990
更新日期:1990-07-01 00:00:00
abstract::Leucine and isoleucine-valine loci have been mapped in Rhizobium japonicum. Transformation analysis suggests a common pathway for isoleucine-valine biosynthesis. Three-point reciprocal crosses indicated that all the leucine loci are not genetically linked. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.126.2.997-998.1976
更新日期:1976-05-01 00:00:00
abstract::The occurrence of the novel regulatory nucleotide bis(3',5')-cyclic diguanylic acid (c-di-GMP) and its relation to cellulose biogenesis in the plant pathogen Agrobacterium tumefaciens was studied. c-di-GMP was detected in acid extracts of 32P-labeled cells grown in various media, and an enzyme responsible for its form...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.171.12.6649-6655.1989
更新日期:1989-12-01 00:00:00
abstract::Crude cell extracts of Bacillus subtilis 168T exhibit enzyme activity capable of releasing free uracil from phage PBS1 deoxyribonucleic acid (DNA) in the presence of ethylenediaminetetraacetate. By measuring the enzyme activity in 300 clones that emanated from mutagenized cells, we obtained a mutant strain that did no...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.131.2.438-445.1977
更新日期:1977-08-01 00:00:00
abstract::Lambda transducing phage gamma 16-2 carries the genes envA, ftsZ, ftsA, ddl, and murC and directs the synthesis of six unique proteins in ultraviolet-irradiated cells. Various derivatives of gamma 16-2 carrying smaller segments of the bacterial deoxyribonucleic acid have also been analyzed for their capacity to direct...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.143.3.1281-1288.1980
更新日期:1980-09-01 00:00:00
abstract::Six mutants, allelic to ade3, were isolated after mutagenic treatment of a prototrophic strain of yeast. All six grow on medium supplemented with adenine alone and four respond to histidine. Supplementation with adenine plus histidine or methionine inhibits growth, but a mixture of these three is stimulatory. Heteroal...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.107.1.1-7.1971
更新日期:1971-07-01 00:00:00
abstract::Ruthenium red stained a capsule external to the exine of the Azotobacter cyst. The central body is therefore surrounded by three layers, the intine, the exine, and the capsule, all containing acid mucopolysaccharide. Vesicles that appear to originate from the contracting cell membrane of the central body may account f...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.102.1.234-239.1970
更新日期:1970-04-01 00:00:00
abstract::The gene encoding the outer membrane phosphate-selective porin protein P from Pseudomonas aeruginosa was cloned into Escherichia coli. The protein product was expressed and transported to the outer membrane of an E. coli phoE mutant and assembled into functional trimers. Expression of a product of the correct molecula...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.170.5.2312-2318.1988
更新日期:1988-05-01 00:00:00
abstract::A number of independently derived uracil-requiring mutant strains of the parent strain 168 were mapped by inter-mutant transformation crosses. Only a few of these mutant strains were found to be transformable. Studies were performed in which these transformable uracil-requiring mutant strains were used as the recipien...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.116.2.577-581.1973
更新日期:1973-11-01 00:00:00
abstract::In all organisms, chromosome replication is regulated mainly at the initiation step. Most of the knowledge about the mechanisms that regulate replication initiation in bacteria has come from studies on rod-shaped bacteria, such as Escherichia coli and Bacillus subtilisStreptomyces is a bacterial genus that is characte...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00597-19
更新日期:2020-01-15 00:00:00
abstract::Fitz-James, Philip (University of Western Ontario, London, Canada). Electron microscopy of Bacillus megaterium undergoing isolation of its nucelar bodies. J. Bacteriol. 87:1202-1210. 1964.-The various steps of treatment leading to the isolation of nuclear bodies were followed by thin-section electron microscopy. Nucle...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.87.5.1202-1210.1964
更新日期:1964-05-01 00:00:00
abstract::A total of 400 suppressible mutations have been isolated in the araC gene of Escherichia coli. Based on deletion mapping, growth patterns when suppressed, and intragenic recombination, 37 mutants have been determined to contain unique mutations. Rapid plate assays were developed to test for each of the three AraC prot...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.154.3.1329-1338.1983
更新日期:1983-06-01 00:00:00
abstract::Xylella fastidiosa is a xylem-limited nonflagellated bacterium that causes economically important diseases of plants by developing biofilms that block xylem sap flow. How the bacterium is translocated downward in the host plant's vascular system against the direction of the transpiration stream has long been a puzzlin...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.187.16.5560-5567.2005
更新日期:2005-08-01 00:00:00
abstract::Rhizobia form a symbiotic relationship with plants of the legume family to produce nitrogen-fixing root nodules under nitrogen-limiting conditions. We have examined the importance of glutathione (GSH) during free-living growth and symbiosis of Sinorhizobium meliloti. An S. meliloti mutant strain (SmgshA) which is unab...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.187.1.168-174.2005
更新日期:2005-01-01 00:00:00
abstract::The staphylococcal virulon is activated by the density-sensing agr system, which is autoinduced by a short peptide (autoinducing peptide [AIP]) processed from a propeptide encoded by agrD. A central segment of the agr locus, consisting of the C-terminal two-thirds of AgrB (the putative processing enzyme), AgrD, and th...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.182.22.6517-6522.2000
更新日期:2000-11-01 00:00:00