A proximity ligation assay (PLA) based sensing platform for the ultrasensitive detection of P53 protein-specific SUMOylation

Abstract Protein SUMOylation is a kind of post-translational modification that closely involves numerous physiological and pathological processes. Because of the important role of SUMOylation in living cells, sensitivity characterization of SUMOylation is urgent for the understanding of SUMOylatin-mediated cellular function. Due to the low- expression of SUMOylated substrate in living cells, a sensitive and selective sensing platform for the assay SUMOylation modification events is highly desired. In this work, we implemented SUMOylation using purified p53 by using the proximity ligation assay (PLA) method. GST-tagged SUMO 1 was employed for the SUMOylation assay. Using the sensing platform, we obtain P53 SUMOylation with ultrasensitivity and selectivity, which equally 83 copy P53 in 1 μL solution. Other forms of SUMOylation are also amenable to profiling by this well-designed strategy. Our PLA sensing platform will also provide a more coherent referential experience on the cellular protein-protein interaction responses that mainly measure expression levels of individual proteins or protein-protein interactions.