Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2008-10-2
pubmed:abstractText
Streptococcus mutans is a primary pathogen for dental caries in humans. CiaR and CiaH of S. mutans comprise a two-component signal transduction system (TCS) involved in regulating various virulent factors. However, the signal that triggers the CiaRH response remains unknown. In this study, we show that calcium is a signal for regulation of the ciaRH operon, and that a double-glycine-containing small peptide encoded within the ciaRH operon (renamed ciaX) mediates this regulation. CiaX contains a serine + aspartate (SD) domain that is shared by calcium-binding proteins. A markerless in-frame deletion of ciaX reduced ciaRH operon expression and diminished the calcium repression of operon transcription. Point mutations of the SD domain resulted in the same phenotype as the in-frame deletion, indicating that the SD domain is required for CiaX function. Further characterization of ciaX demonstrated that it is involved in calcium-mediated biofilm formation. Furthermore, inactivation of ciaR or ciaH led to the same phenotype as the in-frame deletion of ciaX, suggesting that all three genes are involved in the same regulatory pathway. Sequence analysis and real-time RT-PCR identified a putative CiaR binding site upstream of ciaX. We conclude that the ciaXRH operon is a three-component, self-regulatory system modulating cellular functions in response to calcium.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1365-2958
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
70
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
112-26
pubmed:dateRevised
2011-9-26
pubmed:meshHeading
pubmed-meshheading:18681938-Amino Acid Sequence, pubmed-meshheading:18681938-Bacterial Proteins, pubmed-meshheading:18681938-Biofilms, pubmed-meshheading:18681938-Calcium, pubmed-meshheading:18681938-Gene Deletion, pubmed-meshheading:18681938-Gene Expression Regulation, Bacterial, pubmed-meshheading:18681938-Genes, Bacterial, pubmed-meshheading:18681938-Genetic Complementation Test, pubmed-meshheading:18681938-Homeostasis, pubmed-meshheading:18681938-Humans, pubmed-meshheading:18681938-Molecular Sequence Data, pubmed-meshheading:18681938-Mutagenesis, Site-Directed, pubmed-meshheading:18681938-Operon, pubmed-meshheading:18681938-Phenotype, pubmed-meshheading:18681938-Point Mutation, pubmed-meshheading:18681938-RNA, Bacterial, pubmed-meshheading:18681938-Reverse Transcriptase Polymerase Chain Reaction, pubmed-meshheading:18681938-Sequence Alignment, pubmed-meshheading:18681938-Signal Transduction, pubmed-meshheading:18681938-Streptococcus mutans
pubmed:year
2008
pubmed:articleTitle
The cia operon of Streptococcus mutans encodes a unique component required for calcium-mediated autoregulation.
pubmed:affiliation
UCLA School of Dentistry, Los Angeles, CA 90095, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural