A sensitive and specific genetically encoded potassium ion biosensor for in vivo applications across the tree of life
2022
Abstract
Potassium ion (K+) plays a critical role as an essential electrolyte in all biological systems. Genetically encoded fluorescent r biosensors are promising tools to further improve our understanding of K+-dependent processes under normal and pathological conditions.
Here, we report the crystal structure of a previously reported genetically encoded fluorescent K+ biosensor, GINKO1, in the K+-bound state. Using structure-guided optimization and directed evolution, we have engineered an improved r biosensor, designated GINKO2, with higher sensitivity and specificity.
We have demonstrated the utility of GINKO2 for in vivo detection and imaging of K+ dynamics in multiple model organisms, including bacteria, plants, and mice.