Fig. 4: USP26 directly interacts with SIRT1.

a A Co-IP assay combined with mass spectrometry analysis was performed to screen for USP26-interacting proteins. A partial list of accession numbers and the matched peptides of candidate proteins is shown. b HEK293T cells were co-transfected with SFB-USP26 and Myc-SIRT1, and then Co-IP was performed using S-protein beads. c The interaction between endogenous USP26 and SIRT1 was measured by Co-IP. Lysates of HCCLM3 cells were immunoprecipitated with an anti-USP26 antibody or nonspecific IgG, and the associated SIRT1 was detected by immunoblotting. d. A GST pull-down assay was carried out to detect the interaction between USP26-His and GST-SIRT1. e His pull-down assay was carried out to detect the interaction between USP26-His and GST-SIRT1. f U2OS cells were transfected with the GFP-USP26 plasmid. The intracellular localization of USP26 (green) and endogenous SIRT1 (red) was visualized by using a laser confocal microscope. Scale bar: 10 μm. g Mapping the ___domain structure of SIRT1 that interacts with USP26. Full-length SIRT1 and its various deletion mutants together with USP26 were co-expressed in HEK293T cells. The binding regions between USP26 and SIRT1 were detected by Co-IP. A schematic diagram is shown above the panel. h The ___domain structure of USP26, which interacts with SIRT1, was measured by Co-IP. The binding regions were detected by Co-IP. A schematic diagram is shown above the panel. The red star (*) in c indicates the position of SIRT1. Data in (b–h) are representative from three independent experiments. Source data are provided as a Source Data file.