scholarly journals Proteomics Reveals a Physical and Functional Link between Hepatocyte Nuclear Factor 4α and Transcription Factor IID

2009 ◽  
Vol 284 (47) ◽  
pp. 32405-32412 ◽  
Author(s):  
Hidehisa Takahashi ◽  
Skylar Martin-Brown ◽  
Michael P. Washburn ◽  
Laurence Florens ◽  
Joan W. Conaway ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Nuclear Factor ◽  
Hepatocyte Nuclear Factor ◽  
Functional Link ◽  
Hepatocyte Nuclear Factor 4Α ◽  
Transcription Factor Iid

scholarly journals Maturity-Onset Diabetes of the Young Type 1 (MODY1)-Associated Mutations R154X and E276Q in Hepatocyte Nuclear Factor 4α (HNF4α) Gene Impair Recruitment of p300, a Key Transcriptional Coactivator

2001 ◽  
Vol 15 (7) ◽  
pp. 1200-1210 ◽  
Author(s):  
Jérôme Eeckhoute ◽  
Pierre Formstecher ◽  
Bernard Laine
Keyword(s):  
Transcription Factor ◽  
Transcriptional Activity ◽  
Cell Function ◽  
Nuclear Factor ◽  
Maturity Onset Diabetes ◽  
Hepatocyte Nuclear Factor ◽  
Β Cell ◽  
Β Cell Function ◽  
Hepatocyte Nuclear Factor 4Α

Abstract Hepatocyte nuclear factor 4α (HNF4α) is a nuclear receptor involved in glucose homeostasis and is required for normal β-cell function. Mutations in the HNF4α gene are associated with maturity-onset diabetes of the young type 1. E276Q and R154X mutations were previously shown to impair intrinsic transcriptional activity (without exogenously supplied coactivators) of HNF4α. Given that transcriptional partners of HNF4α modulate its intrinsic transcriptional activity and play crucial roles in HNF4α function, we investigated the effects of these mutations on potentiation of HNF4α activity by p300, a key coactivator for HNF4α. We show here that loss of HNF4α function by both mutations is increased through impaired physical interaction and functional cooperation between HNF4α and p300. Impairment of p300-mediated potentiation of HNF4α transcriptional activity is of particular importance for the E276Q mutant since its intrinsic transcriptional activity is moderately affected. Together with previous results obtained with chicken ovalbumin upstream promoter-transcription factor II, our results highlight that impairment of recruitment of transcriptional partners represents an important mechanism leading to abnormal HNF4α function resulting from the MODY1 E276Q mutation. The impaired potentiations of HNF4α activity were observed on the promoter of HNF1α, a transcription factor involved in a transcriptional network and required for β-cell function. Given its involvement in a regulatory signaling cascade, loss of HNF4α function may cause reduced β-cell function secondary to defective HNF1α expression. Our results also shed light on a better structure-function relationship of HNF4α and on p300 sequences involved in the interaction with HNF4α.

scholarly journals Quantitative Proteomics Identifies DNA Repair as a Novel Biological Function for Hepatocyte Nuclear Factor 4α in Colorectal Cancer Cells

Cancers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 626 ◽  
Author(s):  
Jean-Philippe Babeu ◽  
Samuel D. Wilson ◽  
Élie Lambert ◽  
Dominique Lévesque ◽  
François-Michel Boisvert ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Dna Damage ◽  
Dna Repair ◽  
Transcription Factor ◽  
Cancer Cells ◽  
Quantitative Proteomics ◽  
Nuclear Factor ◽  
Hepatocyte Nuclear Factor ◽  
Colorectal Cancer Cells ◽  
Hepatocyte Nuclear Factor 4Α

Hepatocyte nuclear factor 4α (HNF4α) is a transcription factor that acts as a master regulator of genes for several endoderm-derived tissues, including the intestine, in which it plays a central role during development and tumorigenesis. To better define the mechanisms by which HNF4α can influence these processes, we identified proteins interacting with HNF4α using stable isotope labelling with amino acids in cell culture (SILAC)-based quantitative proteomics with either immunoprecipitation of green fluorescent protein (GFP) or with proximity-dependent purification by the biotin ligase BirA (BioID), both fused to HNF4α. Surprisingly, these analyses identified a significant enrichment of proteins characterized with a role in DNA repair, a so far unidentified biological feature of this transcription factor. Several of these proteins including PARP1, RAD50, and DNA-PKcs were confirmed to interact with HNF4α in colorectal cancer cell lines. Following DNA damage, HNF4α was able to increase cell viability in colorectal cancer cells. Overall, these observations identify a potential role for this transcription factor during the DNA damage response.

scholarly journals The MODY1 Gene for Hepatocyte Nuclear Factor 4α and a Feedback Loop Control COUP-TFII Expression in Pancreatic Beta Cells

2008 ◽  
Vol 28 (14) ◽  
pp. 4588-4597 ◽  
Author(s):  
Anaïs Perilhou ◽  
Cécile Tourrel-Cuzin ◽  
Pili Zhang ◽  
Ilham Kharroubi ◽  
Haiyan Wang ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Insulin Secretion ◽  
Binding Site ◽  
Beta Cells ◽  
Pancreatic Beta Cells ◽  
Gene Promoter ◽  
Mrna Levels ◽  
Nuclear Factor ◽  
Hepatocyte Nuclear Factor ◽  
Hepatocyte Nuclear Factor 4Α

ABSTRACT Pancreatic islet beta cell differentiation and function are dependent upon a group of transcription factors that maintain the expression of key genes and suppress others. Knockout mice with the heterozygous deletion of the gene for chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII) or the complete disruption of the gene for hepatocyte nuclear factor 4α (HNF4α) in pancreatic beta cells have similar insulin secretion defects, leading us to hypothesize that there is transcriptional cross talk between these two nuclear receptors. Here, we demonstrate specific HNF4α activation of a reporter plasmid containing the COUP-TFII gene promoter region in transfected pancreatic beta cells. The stable association of the endogenous HNF4α with a region of the COUP-TFII gene promoter that contains a direct repeat 1 (DR-1) binding site was revealed by chromatin immunoprecipitation. Mutation experiments showed that this DR-1 site is essential for HNF4α transactivation of COUP-TFII. The dominant negative suppression of HNF4α function decreased endogenous COUP-TFII expression, and the specific inactivation of COUP-TFII by small interfering RNA caused HNF4α mRNA levels in 832/13 INS-1 cells to decrease. This positive regulation of HNF4α by COUP-TFII was confirmed by the adenovirus-mediated overexpression of human COUP-TFII (hCOUP-TFII), which increased HNF4α mRNA levels in 832/13 INS-1 cells and in mouse pancreatic islets. Finally, hCOUP-TFII overexpression showed that there is direct COUP-TFII autorepression, as COUP-TFII occupies the proximal DR-1 binding site of its own gene in vivo. Therefore, COUP-TFII may contribute to the control of insulin secretion through the complex HNF4α/maturity-onset diabetes of the young 1 (MODY1) transcription factor network operating in beta cells.

scholarly journals Identification of the Flavonoid Luteolin as a Repressor of the Transcription Factor Hepatocyte Nuclear Factor 4α

2015 ◽  
Vol 290 (39) ◽  
pp. 24021-24035 ◽  
Author(s):  
Juan Li ◽  
Jun Inoue ◽  
Jung-Min Choi ◽  
Shugo Nakamura ◽  
Zhen Yan ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Nuclear Factor ◽  
Hepatocyte Nuclear Factor ◽  
Hepatocyte Nuclear Factor 4Α

scholarly journals The G115S mutation associated with maturity-onset diabetes of the young impairs hepatocyte nuclear factor 4α activities and introduces a PKA phosphorylation site in its DNA-binding domain

2004 ◽  
Vol 383 (3) ◽  
pp. 573-580 ◽  
Author(s):  
Bénédicte OXOMBRE ◽  
Mostafa KOUACH ◽  
Ericka MOERMAN ◽  
Pierre FORMSTECHER ◽  
Bernard LAINE
Keyword(s):  
Transcription Factor ◽  
Dna Binding ◽  
Transcriptional Activity ◽  
Phosphorylation Site ◽  
Binding Domain ◽  
Nuclear Factor ◽  
Dna Binding Domain ◽  
Maturity Onset Diabetes ◽  
Hepatocyte Nuclear Factor ◽  
Hepatocyte Nuclear Factor 4Α

HNF4α (hepatocyte nuclear factor 4α) belongs to a complex transcription factor network that is crucial for the function of hepatocytes and pancreatic β-cells. In these cells, it activates the expression of a very large number of genes, including genes involved in the transport and metabolism of glucose and lipids. Mutations in the HNF4α gene correlate with MODY1 (maturity-onset diabetes of the young 1), a form of type II diabetes characterized by an impaired glucose-induced insulin secretion. The MODY1 G115S (Gly115→Ser) HNF4α mutation is located in the DNA-binding domain of this nuclear receptor. We show here that the G115S mutation failed to affect HNF4α-mediated transcription on apolipoprotein promoters in HepG2 cells. Conversely, in pancreatic β-cell lines, this mutation resulted in strong impairments of HNF4α transcriptional activity on the promoters of LPK (liver pyruvate kinase) and HNF1α, with this transcription factor playing a key role in endocrine pancreas. We show as well that the G115S mutation creates a PKA (protein kinase A) phosphorylation site, and that PKA-mediated phosphorylation results in a decreased transcriptional activity of the mutant. Moreover, the G115E (Gly115→Glu) mutation mimicking phosphorylation reduced HNF4α DNA-binding and transcriptional activities. Our results may account for the 100% penetrance of diabetes in human carriers of this mutation. In addition, they suggest that introduction of a phosphorylation site in the DNA-binding domain may represent a new mechanism by which a MODY1 mutation leads to loss of HNF4α function.

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