Fig. 5: Kindlin-2 interacts with and inactivates STAT3 by competitively blocking JAK2/STAT3 interaction.

A Volcano plot showing differential expression genes of myoepithelial cells between K14-Cre + ; Kindlin-2^flox/flox group and K14-Cre-; Kindlin-2^flox/flox group. Absolute (Log2(foldchange)) >0.5, P value < 0.05. B Heatmap showing relative transcription factor activity among three groups. C Venn Diagram showing the intersection of relative activated transcription factors in K14-Cre + ; Kindlin-2^flox/flox myoepithelial cell and Kindlin-2 binding protein. D Boxplot showing the mRNA expression levels of Stat3 canonical target genes and Kindlin-2 in myoepithelial cells from each group. Statistical testing was performed by unpaired wilcox-test. *P < 0.05, **P < 0.01, ***P < 0.001. E Co-immunoprecipitation assays were performed using lysates from MDA-MB-231 cells with control immunoglobulin G (IgG) or anti-Kindlin-2 antibody, followed by immunoblotting with an anti-STAT3 antibody. F Co-immunoprecipitation assays were performed using lysates from HEK293T cells with control immunoglobulin G (IgG) or anti-Kindlin-2 antibody, followed by immunoblotting with an anti-STAT3 antibody. G Western blot analysed of STAT3, STAT3 pY705, and STAT3 pS727 using specific antibodies through loss of function of Kindlin-2 in the cell lines: MDA-MB-231. GAPDH acted as an internal reference. H Control and Kindlin-2 siRNAs were transiently transfected into MDA-MB-231 cells separately. After 72 h, total protein extraction was prepared and a coIP assay was performed using anti-JAK2 antibody. Western blot was performed to detect STAT3 and JAK2 using specific antibodies. GAPDH acted as an internal reference. I Western blot showing the expression of Kindlin-2, STAT3, STAT3 pY705, STAT3 pS727, and Dll1 in liver, kidney, colorectal, and skeletal muscle in Kindlin-2 knockout-first (KO-First) and control mice (WT). J Immunohistochemical staining for Kindlin-2, STAT3, STAT3 pY705, and Dll1expression at the age of 8 weeks in Kindlin-2^fl/fl; MYH-cre+ and Kindlin-2^fl/fl; MYH-cre- control mice. Scale bar, 50 µm.