Fig. 4

FOXK2-142aa interacts with LDHA and regulates its phosphorylation at the Tyr10 site in HCC. A The peptides of LDHA were identified by MS assay. B Co-IP with antibody against LDHA and FOXK2-142aa followed by Western blotting respectively using FOXK2-142aa and LDHA antibodies. C circFOXK2 overexpression plasmid was transfected into HepG2 and Huh7 cells, and immunofluorescence was conducted using anti-LDHA (fluorescent red) and anti-Flag (fluorescent green) antibodies. The nucleus was investigated by DAPI staining (fluorescent blue). (Bar = 2 μm). D Schematic diagrams showed the domain structure of LDHA and GFP-tagged LDHA mutants. E HEK-293 T cells were transfected with Flag-tagged FOXK2-142aa and GFP-tagged full-length or LDHA fragments, followed by performing an IP assay with an anti-Flag antibody. F Schematic of the wild-type FOXK2-142aa and its truncation mutants. G HEK-293 T cells were transfected with Flag-tagged FOXK2-142aa mutants and GFP-tagged LDHA, followed by conducting an IP assay with an anti-GFP antibody. H Western blot assay was performed to detect the level of phosphorylated LDHA in cells after transfected with wild-type FOXK2-142aa ORF or truncation mutants. I-K Alterations in pyruvate production, lactate production and ATP production levels were analyzed. L-M The ECAR and OCR in HepG2 and Huh7 cells were measured. Data were represented as means ± SD with at least three independent experiments. *p < 0.05, **p < 0.01, ***p < 0.001