title: Fat mass and obesity associated gene (FTO) expression is regulated negatively by the transcription factor Foxa2.
abstract: Fat mass and obesity associated gene (FTO) is the first gene associated with body mass index (BMI) and risk for diabetes. FTO is highly expressed in the brain and pancreas, and is involved in regulating dietary intake and energy expenditure. To investigate the transcriptional regulation of FTO expression, we created 5'-deletion constructs of the FTO promoter to determine which transcription factors are most relevant to FTO expression. The presence of an activation region at -201/+34 was confirmed by luciferase activity analysis. A potential Foxa2 (called HNF-3β) binding site and an upstream stimulatory factor (USF)-binding site was identified in the -100 bp fragment upstream of the transcription start site (TSS). Furthermore, using mutagenesis, we identified the Foxa2 binding sequence (-26/-14) as a negative regulatory element to the activity of the human FTO promoter. The USF binding site did not affect the FTO promoter activity. Chromatin immunoprecipitation (ChIP) assays were performed to confirm Foxa2 binding to the FTO promoter. Overexpression of Foxa2 in HEK 293 cells significantly down-regulated FTO promoter activity and expression. Conversely, knockdown of Foxa2 by siRNA significantly up-regulated FTO expression. These findings suggest that Foxa2 negatively regulates the basal transcription and expression of the human FTO gene.
authors.affiliation: Department of Endocrinology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China.
authors.forename: Jianjin
authors.initials: J
authors.lastname: Guo
authors.forename: Wei
authors.initials: W
authors.lastname: Ren
authors.forename: Ying
authors.initials: Y
authors.lastname: Ding
authors.forename: Aimei
authors.initials: A
authors.lastname: Li
authors.forename: Lu
authors.initials: L
authors.lastname: Jia
authors.forename: Dongming
authors.initials: D
authors.lastname: Su
authors.forename: Xiang
authors.initials: X
authors.lastname: Liu
authors.forename: Kuanfeng
authors.initials: K
authors.lastname: Xu
authors.forename: Tao
authors.initials: T
authors.lastname: Yang
mesh_terms: D000071516:Alpha-Ketoglutarate-Dependent Dioxygenase FTO; D024202:Electrophoretic Mobility Shift Assay; D015870:Gene Expression; D005786:Gene Expression Regulation; D057809:HEK293 Cells; D006367:HeLa Cells; D051542:Hepatocyte Nuclear Factor 3-beta / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D016297:Mutagenesis, Site-Directed; D011401:Promoter Regions, Genetic; D011506:Proteins / Q000235:genetics* / Q000378:metabolism; D034741:RNA, Small Interfering
chemical_list: C496502:FOXA2 protein, human; D011506:Proteins; D034741:RNA, Small Interfering; D051542:Hepatocyte Nuclear Factor 3-beta; D000071516:Alpha-Ketoglutarate-Dependent Dioxygenase FTO; C526492:FTO protein, human