PIEZO1

Piezo-type mechanosensitive ion channel component 1 is a protein that in humans is encoded by the PIEZO1 gene. PIEZO1 is a large mechanosensitive ion channel protein that forms a homotrimeric complex with a distinctive three-bladed, propeller-shaped architecture. Each subunit of PIEZO1 contains between 30 and 40 transmembrane domains. The protein consists of a central pore module and peripheral mechanotransduction modules. The pore module is composed of the last two transmembrane helices, an extracellular cap domain, and an intracellular C-terminal domain.

PIEZO1 functions as a non-selective cation channel capable of conducting both monovalent and divalent cations, including Na+, K+, and Ca2+. The mechanosensitivity of PIEZO1 is a defining characteristic. It can be directly activated by membrane tension, with the peripheral blade and beam structures likely acting as mechanotransduction modules. Notably, PIEZO1 requires lower tension for activation compared to bacterial mechanosensitive channels. The protein exhibits voltage-dependent inactivation. PIEZO1 serves as a mechanotransducer in various cell types and tissues playing roles in processes such as vascular development, red blood cell volume regulation, and epithelial homeostasis.

Piezo1 and its close homolog Piezo2 were cloned in 2010, using an siRNA-based screen for mechanosensitive ion channels.