The persistence of
neurodegenerative diseases has necessitated
the development of new strategies to monitor protein homeostasis (proteostasis).
Previous efforts in our laboratory have focused on the development
of fluorogenic strategies to observe the onset and progression of
proteostatic stress. These works utilized solvatochromic and viscosity
sensitive fluorophores to sense protein folded states, enabling stressor
screening with an increase in the emission intensity upon aggregation.
In this work, we present a novel, high-fidelity assay to detect perturbations
of cellular proteostasis, where the fluorescence intensity decreases
with the onset of proteostatic stress. Utilizing a fluorogenic, hydroxymethyl
silicon-rhodamine probe to differentiate between protein folded states,
we establish the validity of this technology in living cells by demonstrating
a two-fold difference in fluorescence intensity between unstressed
and stressed conditions.