Benzo[a]phenoselenazine-based photosensitizer for proximity labeling

Abstract

<p>The molecular interactions within cells are the basis for maintaining cell stability and play an important role. To identify such interactions between molecules, scientists have developed the concept of proximity labeling and developed many tools including APEX, TurboID, and miniSOG systems. These enzymatic-based strategies have been widely used for mapping molecules interactions in cells. However, some shortages also need to dissolve: Enzyme-based proximity labeling methods always need several steps to co-expressed fusion protein which is not convenient enough. Meanwhile, the fusion protein may not have the same function as natural protein which may give us misinformation about the molecule interactions in the cells. Our lab hopes to use chemical ways to overcome these disadvantages in current methods and achieve localization and labeling through chemicals. Here we developed the Benzo[a]phenoselenazine (shorted as SeNB) based proximity labeling method, which can localize in the presence of lipid membranes and can produce singlet oxygen (¹O₂) with red to near-infrared light irradiation. The guanosines and amino acids, which were oxidized by limit area ¹O², and then can react with the alkyne handle in a concise time by reacting with propargyl amine (PA) in the labeling step. Subsequently, the samples would be lysed and biotin or other fluoresce dyes can conjugate with proteins or RNAs through Copper-catalyzed azide–alkyne cycloaddition (CuAAC). The proteomics analysis and RT-qPCR demonstrated that SeNB could apply to proximity labeling in live cells with high spatiotemporal resolution. We anticipate that our tool can help people study molecular interactions in the cells from a new view.</p>