The methylation of C/EBP β gene promoter and regulated by GATA-2 protein.
Mammalian genomes are punctuated by DNA sequences containing an atypically high frequency of CpG sites (CpG islands; CGIs) that are associated with the majority of annotated gene promoters. Methylated C bases of CpG sites inhibit the expression of downstream genes. During the differentiation of 3T3-L1 preadipocytes, the CCAAT/enhancer-binding protein (C/EBP) β gene plays an important role. We studied the CpG island methylation status of the C/EBP β promoter and its relationship with the GATA-2 protein. We used computer analysis to determine that the C/EBP β promoter sequence is rich in CGIs, and observed that two of seven methylated C bases were demethylated during the preadipocyte differentiation using bisulfite sequencing PCR (BSP). This corresponded with the onset of notable C/EBP β gene expression. Immunofluorescence and molecular docking showed that the GATA-2 protein binds the C/EBP β promoter in front of the first demethylated CpG site. We also found that expression of GATA-2 and C/EBP β proteins is negatively correlated. These results indicate that the methylated C bases in the C/EBP β promoter relate to expression of the C/EBP β gene, and that its demethylation is linked with GATA-2 protein association.
Department of Molecular Genetics, Shanghai Medical School, Fudan University, Key Laboratory of Molecular Medicine, Ministry of Education, Shanghai, 200032, China. wanrui_7@hotmail.com
Wan
W
Rui
Zhang
Z
Jin
Gen
G
Zhe
Houyan
H
Song
D041721:3T3-L1 Cells; D017667:Adipocytes / Q000378:metabolism / Q000502:physiology; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D022782:CCAAT-Enhancer-Binding Protein-beta / Q000235:genetics* / Q000378:metabolism; D002454:Cell Differentiation; D018899:CpG Islands; D019175:DNA Methylation; D044127:Epigenesis, Genetic; D050989:GATA2 Transcription Factor / Q000502:physiology*; D015870:Gene Expression; D051379:Mice; D062105:Molecular Docking Simulation; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D017422:Sequence Analysis, DNA
D022782:CCAAT-Enhancer-Binding Protein-beta; C545013:Cebpb protein, mouse; D050989:GATA2 Transcription Factor; C494712:Gata2 protein, mouse