TET2 is recruited by KMT2D to facilitate self-transcription. A) Mutations in IDH1/2–TET2 axis and KMT2D display mutual exclusivity in LIHC. B, C) TET2 interacts with KMT2D. Whole cellular extracts were subjected to IP using the indicated antibodies in HepG2 cells (B). Immunofluorescence analysis using indicated antibodies was performed (C). D) Structural description of TET2-truncated mutants. E) Structural description of KMT2D domains. F) 239T cells stably expressing HA-tagged indicated KMT2D domains were transfected with indicated TET2-truncated mutants. Whole cellular extracts were subjected to IP using beads conjugated with antibody against HA. Immunoblotting analysis was performed using the indicated antibodies. G) Docking analysis of PHD6 domain of KMT2D (PDB accession code: 8U2Y) and C terminus of TET2 (PDB accession code: 4NM6). H) PD assay of TET2 CD and KMT2D PHD6. TET2 CD was purified from 293T cells stably expressing Flag-tagged TET2 CD. KMT2D PHD6 was purified from E. coli expressing GST-tagged PHD6. PD. I) ChIP assay was performed in sgCtrl and sgKMT2D HepG2 cells using antibodies against TET2. DNA enrichment was examined by quantitative real-time PCR. The y axis shows the value normalized to input. ChIP assay was performed in sgCtrl and sgKMT2D HepG2 cells transfected with or without WT and R1896S TET2 using antibodies against 5mC (J) and 5hmC (K). DNA enrichment was examined by quantitative real-time PCR. The y axis shows the value normalized to input. L) ChIP assay was performed in HepG2 cells using antibodies against KMT2D. DNA enrichment was examined by quantitative real-time PCR. The y axis shows the value normalized to input. M) ChIP assay was performed in HepG2 cells using antibodies against H3K4me1, H3K4me2, and H3K4me3. DNA enrichment was examined by quantitative real-time PCR. The y axis shows the value normalized to input. N) Schematic of self-transcription of KMT2D by recruiting TET2 to its promoter. Data are presented as mean ± SD, n = 3 independent repeats. Unpaired, two-tailed t test; **P < 0.01. NS, not significant.