Determining protein acetylation by immunoprecipitation and immunoblotting can be challenging, especially if the tissue of interest is low in quantity, and when good quality acetylation site-specific antibodies are not available. Proximity ligation assays allow a sensitive and quantitative method to assess Foxp3 acetylation in regulatory T cells, with as little as 1.5 × 105 cells within two days turnaround time. This method is of potential use in other similar scenarios, when post-translational modifications of a protein of interest need to be determined with only a small amount of sample and in the absence of specific antibodies that can assess the post-translational modification in the protein of interest.
Keywords: Immunoblot; Immunopreciptation; Protein acetylation; Proximity ligation assay.