Functional biology of ion channels: a review

Abstract

Over the past few decades, a great deal of attention has been focused on discovering the protein partners that form mechanoelectrical transduction (MeT) channels in somatic mechanoreceptors. Two classes of ion channel proteins are leading candidates: amiloride-sensitive channel (ASCs) and transient receptor potential (TRP) channel proteins. Here, we surveyed the literature to establish that most, if not all mechanoreceptor neurons in mice express multiple ASC and TRP channel proteins. But, the landscape of ion channel co-expression in mechanoreceptor neurons is only beginning to be mapped. Future work aimed at refining such maps for mammalian mechanoreceptor neurons will be critical for deeper understanding. Also, each of these potential MeT channel subunits operates within a large company of other ion channel actors that increase the complexity, flexibility, and robustness of somatosensory neuron function. Recently, two additional classes of membrane proteins (Piezo and TMC) have been linked to mechano-transduction. This situation is likely to exist in other mechanoreceptor neurons, including those responsible for touch and pain sensation in mammals.