Fig. 1: Nuclear METTL3 is decreased in the NASH livers.

a–c METTL3 protein levels in nuclei, cytosol, and total cell lysate from the livers of db/db (11 weeks old) mice and HFD (for 8 weeks)- or MCD (for 3 weeks)-fed mice were measured by immunoblotting. The quantification was shown in Supplementary Fig. 1d–f. d Immunoblotting of METTL3 protein levels in nuclei, cytosol, and total cell lysate from human NASH and normal liver tissues. The quantification was shown in Supplementary Fig. 1g. e Primary hepatocytes were isolated and treated with TNFα (20 ng/ml) for 2 h. METTL3 protein levels in nuclei, cytosol, and total cell lysate were measured by immunoblotting. The quantification was shown in Supplementary Fig. 1i. f Primary hepatocytes were infected with Ad-Flag-METTL3 adenovirus, and then treated with or without TNFα (20 ng/ml) for 2 h. The total cell lysate was immunoprecipitated with anti-phosphoserine antibody and immunoblotted with anti-Flag antibody. g Myc-CDK9 expression vector was co-transfected with or without Flag-METTL3 expression vector in HEK293T cells. Total cell lysates were immunoprecipitated with Flag beads and then immunoblotted with anti-Myc or anti-Flag antibodies. h In vitro kinase assay. i Primary hepatocytes were treated with vehicle, TNFα (20 ng/ml), and TNFα (20 ng/ml) plus BAY-1143572 (2 μM) for 2 h. In TNFα plus BAY-1143572 group, primary hepatocytes were pretreated with BAY-1143572 (2 μM) for 2 h. METTL3 protein levels in nuclei, cytosol, and total cell lysate were measured by immunoblotting. CDK9, p-CDK9, Lamin B1, and Tubulin levels were also measured by immunoblotting. The quantification was shown in Supplementary Fig. 1m–n. The samples were derived from the same experiment and the blots were processed in parallel. n was the number of biologically independent mice or cell samples. The cell culture experiments were repeated three times independently with similar results. Source data are provided as a Source Data file.