Fig. 4

P300/SP1 complex regulates the transcriptional activity of METTL1. A GENECARD, PROMO, and JASPAR databases were used to predict the potential transcription factor (TF) of METTL1. B-D Effect of SP1 knockdown on METTL1 mRNA (B-C) and protein (D) levels. E Predicting the combination of SP1 and P300 with the online tool STRING. F Co-immunoprecipitations assay (Co-IP) was performed to verify the interaction between SP1 and P300. G Transcriptional regulation of SP1 and/or P300 on METTL1 expression was performed using a luciferase reporter assay in Cos7 cells. H-K CHIP-qPCR was implemented to prove the combination between SP1 (H-I) or P300 (J-K) and METTL1 promoter region in LNCaP-AI and C4-2 cells directly and indirectly. L-O CHIP-qPCR was used to determine the enrichment of P300 (L-M) or SP1 (N-O) at the promoter of METTL1 in control and SP1 or P300 deficiency LNCaP-AI and C4-2 cells. **P < 0.01; ***P < 0.001; ****P < 0.0001