Scientists have taken a major step forward in understanding how certain proteins sense and respond to mechanical forces, such as pressure, providing critical insights into how cells perceive their environment and respond to external stimuli. These proteins, called Piezo proteins, play vital roles in various physiological processes, including touch sensation, hearing, and blood pressure regulation.

Using a combination of advanced techniques, researchers at the University of California, San Francisco (UCSF) have uncovered the fundamental mechanisms by which Piezo proteins convert mechanical signals into electrical signals. Their findings, published in the journal Nature, shed light on the molecular basis of pressure sensation and pave the way for potential therapeutic interventions targeting Piezo proteins in various diseases.

Piezo proteins are ion channels that allow ions to flow across the cell membrane, altering the electrical potential of the cell. Previous studies had identified Piezo proteins as essential components of mechanosensory neurons, which sense and respond to mechanical stimuli. However, the exact mechanism of how these proteins convert mechanical force into electrical signals remained elusive.

In the current study, the researchers focused on Piezo1, one of the two known Piezo proteins in mammals. Using cryo-electron microscopy (cryo-EM), a cutting-edge technique for visualizing proteins at the atomic level, the researchers captured detailed images of Piezo1 in different conformations. This allowed them to identify key structural changes that occur in response to mechanical force.

The researchers found that Piezo1 is composed of three blades that form a propeller-like structure. When mechanical force is applied, these blades rotate relative to each other, causing the channel to open and allow ions to flow. This conformational change is triggered by a specific region of the protein called the "gating spring," which acts like a molecular switch.

"We found that the gating spring is a flexible linker that connects two of the blades," explains senior author Dr. Yifan Cheng, a professor of cellular and molecular pharmacology at UCSF. "When force is applied, this linker is stretched, leading to the rotation of the blades and the opening of the channel."

This study provides a structural basis for understanding how Piezo proteins function as mechanical sensors. It could have implications for the development of drugs that target Piezo proteins to modulate mechanosensation, potentially leading to new treatments for conditions such as chronic pain, hearing loss, and cardiovascular diseases.

"Our findings advance our understanding of how Piezo proteins work and open new avenues for exploring the role of these proteins in human health and disease," says Dr. Cheng.