Sequence conservation and structural features that are common within TRP channels

Abstract

TRP proteins are a large family of cation selective channels, surpassed in variety only by voltage-gated potassium channels. Detailed molecular mechanisms governing how membrane voltage, ligand binding, or temperature can induce conformational changes promoting the open state of the channel are still missing for TRP channels. Aiming to unveil distinctive structural features common to the transmembrane domains within the TRP family, we performed bioinformatic analyses over a large set of TRP channel genes. Here we report a discrete and exceptionally conserved set of residues. This fingerprint is composed of eleven residues localized at equivalent three-dimensional positions in TRP channels from the different subtypes. Moreover, these amino acids are arranged in three groups, connected by a set of aromatics located at the core of the transmembrane structure. We hypothesize that differences in the connectivity between these different groups of residues harbors the apparent differences in coupling strategies used by TRP subgroups.