Regular use of fluoride-containing toothpaste and mouthwash has long been known to strengthen the enamel on teeth. But new research by Howard Hughes Medical Institute (HHMI) scientists finds that fluoride also has dramatic effects on bacteria inside the mouth -- including those that form plaque and can cause cavities.
HHMI researcher Ronald Breaker of Yale University has discovered the cellular chain of events that occurs inside a bacterium after it encounters fluoride in its environment. His team's findings reveal that many bacteria try to fend off fluoride which the organisms treat as a toxic substance by throwing it out. The presence of such a transport system indicates that fluoride itself has antimicrobial properties, Breaker said. The findings are published online in Science Express on December 22, 2011.
Breaker's lab studies non-coding RNA, stretches of genetic material that play regulatory roles in the cell instead of coding for proteins. Using different computer algorithms, he and his colleagues analyze the genomes of organisms to identify signature sequences in genetic material that likely indicate the presence of noncoding RNA. Among the types of non-coding RNAs they find are regulatory molecules called riboswitches. Normally, the role of a riboswitch is easy to deduce: Riboswitches are attached to the genes that they regulate. If the gene is needed to produce a certain compound, the riboswitch is usually sensitive to that compound, so when its level increases or decreases in the cell, the riboswitch can cause more or less to be made. Aside from their interest in the biology of riboswitches, Breaker's group is studying these genetic switches because they could represent new drug targets and might be used to control the activity of genes inserted into cells as gene therapies.
In a recent set of experiments, Breaker's team identified a new riboswitch that was attached to a handful of genes with vague or unknown functions. They w
|Contact: Jim Keeley|
Howard Hughes Medical Institute