Craig Montell, Ph.D.

The TRP superfamily of cation channels is comprised of 28 mammalian members as well as 13 Drosophila proteins, all of which are permeable to cations, contain six transmembrane segments and exhibit varying degrees of sequence homology. However, TRP channels are remarkable in their diversity of biological functions, cation selectivities and activation mechanisms. Nevertheless, a recurring theme is that TRP channels play important roles in sensory physiology.

We identified the first member of the TRP superfamily as part of our characterization of Drosophila visual transduction. We found that TRP associates with a supramolecular signaling complex, the signalplex, which includes many of the proteins required for visual transduction. However, some proteins, such as the rhodopsin regulatory protein, arrestin, which do not bind directly to the signalplex, undergo rapid light dependent shuttling in the photoreceptor cells. We showed that the dynamic movements of arrestin functions in adaptation and is mediated by phosphoinositide-dependent interactions with the NINAC myosin III.

Most recently, our laboratory has identified and characterized the roles of several additional Drosophila TRP channels that function in other sensory modalities. Finally, we have initiated a new project to exploit Drosophila as a model to study the relationship of TRP channels and neurodegenerative disease.