Fig. 3
From: STAT3 associates with vacuolar H+-ATPase and regulates cytosolic and lysosomal pH
STAT3 interacts with V-ATPase via its coiled-coil domain. a Domain structure of STAT3 with mutations used in b indicated below. SH2, Src homology 2 domain; TAD, transactivation domain. b Quantification of PLA (anti-Flag and anti-ATP6V1A) puncta in HeLa cells expressing the indicated Flag-tagged STAT3 constructs (top). Error bars, SD of three independent experiments with ≥ 10 cells analyzed/sample. P-values were calculated by one-way ANOVA combined with Dunnett’s multiple comparisons test. Rough estimates of the relative expression levels of Flag-tagged STAT3 constructs are shown below the histogram as percentages of the expression of the wild-type STAT3. See Supplementary information, Fig. S3b for representative immunoblots. Bottom, representative images of PLAs taken with 60× magnification using Zeiss LSM700 confocal microscope. The optimal slice thickness (∼350 nm) was defined by the Zeiss zen software. Lysosomes were visualized with cascade blue dextran. Scale bar, 10 µm. c Representative immunoblots of the indicated proteins in total cell lysates or the indicated fractions of HeLa-STAT3-KO cells reconstituted with STAT3-Y705F (20 µg protein/lane). n = 3
