•A light-switchable degron allows rapid and specific degradation of target protein.•The light-switchable degron is light irradiance dependent.•The light-switchable degron can be used to mediate degradation of a secreted protein.Controlling protein degradation can be a valuable tool for posttranslational regulation of protein abundance to study complex biological systems. In the present study, we designed a light-switchable degron consisting of a light oxygen voltage (LOV) domain of Avena sativa phototropin 1 (AsLOV2) and a C-terminal degron. Our results showed that the light-switchable degron could be used for rapid and specific induction of protein degradation in HEK293 cells by light in a proteasome-dependent manner. Further studies showed that the light-switchable degron could also be utilized to mediate the degradation of secreted Gaussia princeps luciferase (GLuc), demonstrating the adaptability of the light-switchable degron in different types of protein. We suggest that the light-switchable degron offers a robust tool to control protein levels and may serves as a new and significant method for gene- and cell-based therapies.Download high-res image (134KB)Download full-size image

Light-switchable gene expression systems provide transient, non-invasive and reversible means to control biological processes with high tunability and spatiotemporal resolution. In bacterial cells, a few light-regulated gene expression systems based on photoreceptors and two-component regulatory systems (TCSs) have been reported, which respond to blue, green or red light1,2,3,4,5.

Ero1p, using molecular oxygen as its preferred terminal electron acceptor, promotes disulfide bond formation by interaction with protein disulfide isomerase. Dysfunction of Ero1p leads to strong activation of the unfolded protein response and marked loss of cell viability. However, modest attenuation of Ero1p improves the fitness of yeast challenged with high levels of protein misfolding in their endoplasmic reticulum stress. Partial inhibition of Ero1p is hence of great significance. In the present paper, a docking-based virtual screening method was performed to identify inhibitors of Ero1p and 12 hits were successfully obtained from 81 purchased compounds with micromolar inhibition against Ero1p. Particularly, six of the hits demonstrated remarkable potency with IC50 <30 μM and held the prospect of becoming lead compounds. Then the interaction modes were analyzed for further lead optimization.