Deciphering Signal Transduction in S. Mutans

June 24, 2005

Scientists have strongly suspected that the tooth-decay-causing bacterium Streptococcus mutans modifies certain aspects of its behavior through a two-component signaling network called vicRK. The network works like this: The first protein component initiates a signal on S. mutans's cell surface, the second component thereafter receives and processes the message, then relays it accordingly to the cytoplasm for an appropriate response. Left unanswered is which type of adaptive behavior the network actually triggers. In the June issue of the Journal of Bacteriology, NIDCR grantees and colleagues provide the answer. The scientists report that vicRK network regulates the bacterium's sucrose-mediated adhesion to tooth enamel, a vital early step in the process that leads to tooth decay. The network also seems to regulate the expression of genes involved in the expression of other virulence factors, although additional research will be needed to better define which genes are involved. As the authors noted, these data could provide valuable molecular targets to more effectively control this destructive oral bacterium.