Linked Life Data

15336418

Source:http://linkedlifedata.com/resource/pubmed/id/15336418

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2004-8-31
pubmed:abstractText
In many streptococci, including Streptococcus mutans, genetic competence is regulated by a quorum sensing system mediated by a competence stimulating peptide (CSP) pheromone, encoded by the comC gene. In Streptococcus pneumoniae, a central component of this system is ComX, which acts as an alternative sigma factor to activate competence genes involved in DNA uptake and processing. The quorum sensing system responsible for genetic competence induction in S. mutans has been linked to biofilm formation and the acid tolerance response. To examine the response of comX to CSP in S. mutans, a transcriptional fusion of the comX promoter (pcomX) with lacZ was constructed to generate reporter vector pcomx::pALH122 (replicative vector) and transformed into S. mutans UA159 comC-, which is unable to produce endogenous CSP. CSP was added and pcomX::lacZ relative expression index (REI) examined, revealing a 2-fold increase in maximal beta-gal activity 5 and 10 min after CSP addition. The effect of endogenous CSP on pcomX::lacZ expression was also examined by measuring REI in cells grown as a biofilm; peak pcomX activity was observed at 3 h. To determine the temporal pattern of transformation frequency, pMA2, a Spr shuttle vector, was transformed into biofilm-grown cells, with maximal transformation frequency observed at 3 h. Confocal microscopy was performed to examine pcomX activity using a similarly constructed green fluorescent protein reporter vector, pcomX::gfp, in a 4-h biofilm, revealing active pcomX activity in high cell density areas within the biofilm population. These results demonstrated a positive correlation between pcomX activity, natural transformation and competence development in biofilms.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0378-1097
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
238
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
167-74
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
ComX activity of Streptococcus mutans growing in biofilms.
pubmed:affiliation
Faculty of Dentistry, University of Toronto, 124 Edward Street, Toronto, Ont., Canada M5G 1G6.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't