# Controlling Piezo channels through optogenetics

> **NIH NIH R21** · STATE UNIVERSITY OF NEW YORK AT BUFFALO · 2020 · $210,540

## Abstract

Mechanosensitive ion channels (MSC) were first observed in chick skeletal muscle in 1984. Recently, a family
of Eukaryotic MSCs, called Piezo, was identified and cloned. These channels sense mechanical forces in a
variety of tissues and allow cells to adapt to mechanical stressors. The channels are abundant in the skin
(Piezo1) and are found in cartilage (Piezo1 and 2). Their functional presence in joints is related to
osteoarthritis. The hereditary disease Arthrogryposis arises from mutations to Piezo2 producing congenital joint
contractures.
We can analyze Piezo channels with high precision in the patch clamp or by whole cell recording but these
measurements do not reflect the in situ channel environment and we have shown that the channel’s response
to stress depends upon the local environment. We propose to modify the Piezo1 channel so that its activity is
controlled optically and this will allow us to study a channel’s contribution to a particular physiological
response.
The Piezo1 protein can accommodate large insertions within the channel (position 1591) and remain
functional, but in some instances the insertion inhibits channel function. The protein can be split at position
1591, and if the segments are co-expressed, they can reassemble into functional channels although neither
half alone is functional. We hypothesize that this region sits at junction involved in protein movement which will
us to control channel function optically. We plan to use the well-known LOV domain in a folded conformation to
prevent a transition to the open state. Then with light stimuli, the LOV domain unfolds and activates the
channel. This reaction is reversible. Specific Aim 1 describes how we intend to introduce the LOV protein into
PIEZO1 to serve as a photoactivatable switch and the ways that we will test channel function using patch
clamp and fluid shear stress stimuli.
A second approach to creating a photoactivated Piezo is described in Specific Aim2. We will determine what
sequences at the split sight (1591) are necessary for formation of the active channel when coexpressed and
remove them. To restore channel function, we will encode protein LOV domain on one channel subunit and a
protein called Zdrk on the other. The LOV-Zdrk proteins interact and the channel is assembled in the dark
(active) and can be dissociated in light (inactivated). We will characterize the property of channel dimerization
in situ and measure channel function.
The overall goal is to develop optically controlled mechanosensitive ion channels thus providing a new tool to
study the physiological response of cells to mechanical stress in situ as well as in vivo and in vitro.

## Key facts

- **NIH application ID:** 9941037
- **Project number:** 5R21AR073463-02
- **Recipient organization:** STATE UNIVERSITY OF NEW YORK AT BUFFALO
- **Principal Investigator:** Philip A Gottlieb
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $210,540
- **Award type:** 5
- **Project period:** 2019-06-05 → 2022-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9941037

## Citation

> US National Institutes of Health, RePORTER application 9941037, Controlling Piezo channels through optogenetics (5R21AR073463-02). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/9941037. Licensed CC0.

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