Mutation P291fsinsC in the Transcription Factor Hepatocyte Nuclear Factor-1  is Dominant Negative

Diabetes ◽  
1998 ◽  
Vol 47 (8) ◽  
pp. 1231-1235 ◽  
Author(s):  
K. Yamagata ◽  
Q. Yang ◽  
K. Yamamoto ◽  
H. Iwahashi ◽  
J.-i. Miyagawa ◽  
...  
Diabetes ◽  
1998 ◽  
Vol 47 (8) ◽  
pp. 1231-1235 ◽  
Author(s):  
K. Yamagata ◽  
Q. Yang ◽  
K. Yamamoto ◽  
H. Iwahashi ◽  
J. Miyagawa ◽  
...  

2013 ◽  
Vol 305 (1) ◽  
pp. F100-F110 ◽  
Author(s):  
Yun-Hee Choi ◽  
Brian T. McNally ◽  
Peter Igarashi

Hepatocyte nuclear factor-1β (HNF-1β) is an epithelial tissue-specific transcription factor that regulates gene expression in the kidney, liver, pancreas, intestine, and other organs. Mutations of HNF-1β in humans produce renal cysts and congenital kidney anomalies. Here, we identify the LIM-domain protein zyxin as a novel binding partner of HNF-1β in renal epithelial cells. Zyxin shuttles to the nucleus where it colocalizes with HNF-1β. Immunoprecipitation of zyxin in leptomycin B-treated cells results in coprecipitation of HNF-1β. The protein interaction requires the second LIM domain of zyxin and two distinct domains of HNF-1β. Overexpression of zyxin stimulates the transcriptional activity of HNF-1β, whereas small interfering RNA silencing of zyxin inhibits HNF-1β-dependent transcription. Epidermal growth factor (EGF) induces translocation of zyxin into the nucleus and stimulates HNF-1β-dependent promoter activity. The EGF-mediated nuclear translocation of zyxin requires activation of Akt. Expression of dominant-negative mutant HNF-1β, knockdown of zyxin, or inhibition of Akt inhibits EGF-stimulated cell migration. These findings reveal a novel pathway by which extracellular signals are transmitted to the nucleus to regulate the activity of a transcription factor that is essential for renal epithelial differentiation.


1995 ◽  
Vol 312 (1) ◽  
pp. 31-37 ◽  
Author(s):  
J Olsen ◽  
I Classen-Linke ◽  
H Sjöström ◽  
O Norén

The rabbit endometrium is an excellent model system allowing experimental manipulation of aminopeptidase N (APN) mRNA expression in vivo. By RNase mapping and sequencing of cloned PCR-amplified primer-extended RNA, it was demonstrated that endometrial APN expression is directed by the epithelial APN promoter and is increased in human-choriogonadotropin-induced pseudopregnancy. Cloning and sequencing of the rabbit APN epithelial promoter revealed conservation of the upstream footprint (UF), hepatocyte nuclear factor-1 (HNF1) and Sp1 elements known to be present in the pig and human promoters as well. The pseudopregnancy-induced APN expression was found to be accompanied by a parallel increase in the level of the transcription factor HNF1 beta, whereas a much smaller increase in Sp1 and UF-binding proteins was observed. This indicates that HNF1 beta acts as a switch triggering the pregnancy-induced APN expression. The sequence of the UF element suggests members of the nuclear hormone-receptor superfamily as possible UF-binding proteins, and competition experiments suggest that the chicken ovalbumin upstream promoter transcription factor functions as such in the rabbit endometrium.


2000 ◽  
Vol 11 (suppl 2) ◽  
pp. S140-S143
Author(s):  
MARCO PONTOGLIO

Abstract. Hepatocyte nuclear factor 1 (HNF1) is a transcription factor involved in the regulation of a large set of hepatic genes, including albumin, β-fibrinogen, and α1-antitrypsin. HNF1 is expressed in the liver, digestive tract, pancreas, and kidney. Mice lacking HNF1 exhibit hepatic, pancreatic, and renal dysfunctions. HNF1-deficient mice fail to express the hepatic phenylalanine hydroxylase gene, giving rise to hyperphenylalaninemia. Renal proximal tubular reabsorption of glucose, phosphate, arginine, and other metabolites is affected, producing severe renal glucosuria, phosphaturia, and amino aciduria. Homozygous mutant mice also exhibit a dramatic insulin secretion defect. This dysfunction resembles that exhibited by patients with maturity-onset diabetes mellitus of the young type 3, who carry mutations in the human HNF1 gene in the heterozygous state. These data show that HNF1 is a major regulator of glucose homeostasis, regulating the expression of genes that are expressed in the liver, kidney, and pancreas.


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