A Complete Look at the Protein behind Sense of Touch

A Complete Look at the Protein behind Sense of Touch

Often ignored when we talk about our fundamental senses, the sensation of touch is a fundamental part of our daily experience. From temperature to texture, your sense of touch has been in constant communication with your brain.

In 2016, a team of scientists revealed that a protein first discovered at TSRI in 2010 is directly responsible for sensing touch. Now, the same team at The Scripps Research Institute (TSRI) have solved the mystery of the structure of Piezo1, a member of a family of proteins that convert physical stimuli such as touch or blood flow into chemical signals.

“This structure provides a fundamental understanding of how proteins sense mechanical force, and will shed light on regions within Piezo1 that can be targeted using small molecules or antibodies,” says Ardem Patapoutian, PhD, a TSRI professor and Howard Hughes Medical Institute investigator, who co-led the new study with TSRI Professor Andrew Ward, PhD.

Piezo1 and Piezo2 are mechanically activated ion channels that mediate touch perception, proprioception and vascular development. Piezos are distinct from other ion channels

and their structure remains poorly defined, impeding detailed study of their gating and ion permeation properties.

When Peizo1 senses mechanical force, it opens to allow ions to pass into the cell, starting a chain of events that send a signal to the brain—in other words; Piezo proteins control the sensation of touch.

In order to further study this proteins’ function and structure in detail, the team carried out with a high-resolution imaging technique called cryo-electron microscopy (cryoEM), shows that Piezo1 is made up of three curved “blades” circling a central pore. The researchers believe these blades move in response to mechanical force, which opens and closes the pore to let ions through to send the signal to communicate touch. A beam-like structure serves as the backbone for each blade. An “anchor domain” surrounds the pore where the blades meet the middle.

The Piezo1 structure is unique because it appears to be an “all-in-one” protein, meaning it does not need to connect with other proteins or cell structures to do its job transmitting a signal.

The researchers state that the next step in this research is to examine the overall architecture of Piezo1 and determine how each piece works. They hope to look at this protein in different conformations besides the closed conformation seen in the current study.