Fig. 2: Sirtuins are required for the deacetylation of v-ATPase.
From: Lithocholic acid binds TULP3 to activate sirtuins and AMPK to slow down ageing
a, Sirtuins are responsible for V1E1 deacetylation and AMPK activation. HEK293T cells were infected with lentiviruses carrying individual wild-type (WT) sirtuins (HA-tagged SIRT1–SIRT7) or their dominant negative (DN) forms, followed by determination of V1E1 acetylation and AMPK activity. b–d, Sirtuins are required for LCA-induced V1E1 deacetylation. Sirt1–7–/– MEFs were treated with 1 μM LCA for 4 h, followed by determination of AMPK activation (b), v-ATPase activity (d; assessed by imaging (left) and quantifying (right) intensities of the lysosensor), and lysosomal localization of AXIN (c; assessed by imaging (left) and quantifying (right) the co-localization of AXIN with the lysosomal marker LAMP2). Scale bars, 6 µm (c) or 10 µm (d). e, Sirtuin members have complementary roles in mediating LCA-induced V1E1 deacetylation and AMPK activation. Sirt1–7–/– MEFs were individually infected with lentivirus carrying seven members of the sirtuin family, followed by treatment with 1 μM LCA for 4 h. AMPK activity and V1E1 acetylation were then determined. f, LCA stimulates the activity of sirtuins. WT and Sirt1–7–/– MEFs were treated with 1 μM LCA for 4 h, followed by determination of H3K9 acetylation (H3K9ac). Statistical results are shown as the mean ± s.e.m. Specific numbers of cells used are labelled on each panel. P values (shown on the charts) were calculated using two-sided Student’s t-test with Welch’s correction (WT, d), two-sided Mann–Whitney test (Sirt1–7–/–, d), or two-way ANOVA followed by Tukey’s text (c). Experiments were performed three (a,c–f) or four (b) times.
