Fig. 2: PAX7 protein interacts with MYST1, SIRT1, and SIRT2.

a PAX7 interacts with MYST1. Cells were transfected with plasmids expressing HA-MYST1 and FLAG-PAX7, as indicated. The interaction between PAX7 and MYST1 was determined by immunoprecipitation using anti-FLAG antibodies (top) or anti-HA antibodies (bottom). Immunoblotting was performed with the indicated antibodies. b PAX7 interacts with SIRT1. Cells were transfected with plasmids expressing HA-SIRT1 and FLAG-PAX7, as indicated. The interaction between PAX7 and SIRT1 was determined by immunoprecipitation using anti-FLAG antibodies (top) or anti-SIRT1 antibodies (bottom). Immunoblotting was performed with the indicated antibodies. c PAX7 interacts with SIRT2. Cells were transfected with plasmids expressing MYC-SIRT2-FLAG and HA-PAX7, as indicated. The interaction between PAX7 and SIRT2 was determined by immunoprecipitation using anti-HA antibodies (top) or anti-FLAG antibodies (bottom). Immunoblotting was performed with the indicated antibodies. d, e Representative confocal images displaying the co-localization between PAX7 and MYST1 (d) or SIRT2 (e). Primary myoblasts were immunostained with PAX7 (red) and MYST1 or SIRT2 (green), and nuclei were counterstained with DAPI (blue). Scale bar represents 10 μm. Images are representative of ≥80% of the cells examined (n = 3 experiments from biologically independent samples). f PAX7 acetylation levels are regulated by MYST1 and SIRT2. Cells were transfected with plasmids encoding PAX7 (WT or K105/193R), MYST1, SIRT2, and SIRT1, and lysates were subjected to immunoprecipitation using anti-acetyl-lysine antibodies. Immunoblotting was performed with the indicated antibodies. g Quantification of the immunoblotting signals from (f). The densitometric analysis of the level of acetylated PAX7, relative to total PAX7 signal, is shown. Data are presented as mean values ± SEM (n = 3 independent experiments) (One-way ANOVA uncorrected Fisher’s LSD test: *p = 0.049).