Novel bacterial quinolone signal molecules and, more particularly,
pseudomonas quinolone signal ("PQS") molecules, e.g.,
2-heptyl-3-hydroxy-4-quinolone, and analogs and derivatives thereof are
described. Therapeutic compositions containing the molecules, and
therapeutic methods, methods of for regulating gene expression, methods
for identifying modulators of the autoinducer molecules, and methods of
modulating quorum sensing signaling in bacteria using the compounds of
the invention are also described.