An endoplasmic reticulum targeting green fluorescent protein chromophore-based probe for the detection of viscosity.

The occurrence of endoplasmic reticulum (ER) stress is the main cause of a variety of biological processes that are closely related to numerous diseases. The homeostasis of the ER microenvironment can be disrupted under ER stress. In this research, by linking a pentafluorophenyl to the green fluorescent protein chromophore, we have developed a new ER-targeting fluorescent probe (GE-Y) for measuring changes of intracellular ER viscosity caused by ER stress. Importantly, an increase in ER viscosity was observed using GE-Y in cells undergoing autophagy. As such, our research provides an ideal tool for studying ER stress and autophagy.