New Modes of GPCR Signalling

ABSTRACT
TRPA1: a Sentinel for Noxious Chemicals and Temperatures
Craig Montell
Department of Biological Chemistry, The Johns Hopkins University School of Medicine
TRP channels endow us with the ability to sense tastants, mechanical stimuli, a variety
of chemicals, distinct temperatures and in some animals, light and pheromones. In this
seminar, I will begin with the identification of the founding member of the TRP family,
which functions in fly phototransduction, and the realization that TRP channels are
global and evolutionarily conserved mediators of sensory signaling in all animals.
I will describe our recent studies demonstrating that the ability of Drosophila larva to
discriminate between the optimal temperature of 18°C and slightly higher temperatures
depends on the TRPA1 channel, which functions downstream of a
phototransduction-like cascade. We propose that activation of TRPA1 via a signaling
cascade, rather than through direct thermal activation, promotes amplification of small
differences in temperature and facilitates adaptation to temperatures within the
comfortable range.
I will summarize our work demonstrating that insect TRPA1 is a target for insect
repellents. Our studies identifies insect TRPA1 as a potential target for developing
improved repellents to reduce insect-borne diseases such as malaria, which cause
significant morbidity and mortality.