Piezo1 is a mechanosensitive ion channel protein that in humans is encoded by the gene PIEZO1. Piezo1 and its close homolog piezo2 were cloned in 2010, using an siRNA-based screen for mechanosensitive ion channels.
PIEZO1 (this gene) and PIEZO2 share 47% identity with each other and they have no similarity to any other protein and contain no known protein domains. They are predicted to have 24-36 transmembrane domains, depending on the prediction algorithm used. In the original publication the authors were careful not to call the piezo proteins ion channels, but a more recent study by the same lab convincingly demonstrated that indeed piezo1 is the pore forming subunit of a mechanosensitive channel.
Piezo1 is expressed in the lungs, bladder and skin, where mechanosensation has important biological roles. Unlike Piezo2 which is highly expressed in sensory dorsal root ganglia, piezo1 is not expressed in sensory neurons.