Type I Protein C Deficiency Caused by Disruption of a Hepatocyte Nuclear Factor (HNF)-6/HNF-1 Binding Site in the Human Protein C Gene Promoter

Abstract Glucagon gene expression in the endocrine pancreas is controlled by three islet-specific elements (G3, G2, and G4) and theα -cell-specific element G1. Two proteins interacting with G1 have previously been identified as Pax6 and Cdx2/3. We identify here the third yet uncharacterized complex on G1 as hepatocyte nuclear factor 3 (HNF-3)β, a member of the HNF-3/forkhead transcription family, which plays an important role in the development of endoderm-related organs. HNF-3 has been previously demonstrated to interact with the G2 element and to be crucial for glucagon gene expression; we thus define a second binding site for this transcription on the glucagon gene promoter. We demonstrate that both HNF-3α and -β produced in heterologous cells can interact with similar affinities to either the G1 or G2 element. Pax6, which binds to an overlapping site on G1, exhibited a greater affinity as compared with HNF-3α or -β. We show that both HNF-3β and -α can transactivate glucagon gene transcription through the G2 and G1 elements. However, HNF-3 via its transactivating domains specifically impaired Pax6-mediated transactivation of the glucagon promoter but had no effect on transactivation by Cdx2/3. We suggest that HNF-3 may play a dual role on glucagon gene transcription by 1) inhibiting the transactivation potential of Pax6 on the G1 and G3 elements and 2) direct activation through G1 and G2.

Download Full-text

Upstream region of rat serum albumin gene promoter contributes to promoter activity: presence of functional binding site for hepatocyte nuclear factor-3

Biochemical Journal ◽

10.1042/0264-6021:3380241 ◽

1999 ◽

Vol 338 (2) ◽

pp. 241 ◽

Cited By ~ 5

Author(s):

Chin-Hui HSIANG ◽

Norman W. MARTEN ◽

Daniel S. STRAUS

Keyword(s):

Serum Albumin ◽

Binding Site ◽

Promoter Activity ◽

Gene Promoter ◽

Upstream Region ◽

Nuclear Factor ◽

Hepatocyte Nuclear Factor ◽

Rat Serum ◽

Albumin Gene ◽

Rat Serum Albumin

Download Full-text

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

Molecular and Cellular Biology ◽

10.1128/mcb.01191-07 ◽

2008 ◽

Vol 28 (14) ◽

pp. 4588-4597 ◽

Cited By ~ 17

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.

Download Full-text

The Frequency of Type I Heterozygous Protein S and Protein C Deficiency in 141 Unrelated Young Patients with Venous Thrombosis

Thrombosis and Haemostasis ◽

10.1055/s-0038-1642558 ◽

1988 ◽

Vol 59 (01) ◽

pp. 018-022 ◽

Cited By ~ 139

Author(s):

C L Gladson ◽

I Scharrer ◽

V Hach ◽

K H Beck ◽

J H Griffin

Keyword(s):

Venous Thrombosis ◽

Protein C ◽

Antithrombin Iii ◽

Young Patients ◽

Protein S ◽

Type I ◽

Protein S Deficiency ◽

Protein C Deficiency ◽

Low Protein ◽

S Deficiency

SummaryThe frequency of heterozygous protein C and protein S deficiency, detected by measuring total plasma antigen, in a group (n = 141) of young unrelated patients (<45 years old) with venous thrombotic disease was studied and compared to that of antithrombin III, fibrinogen, and plasminogen deficiencies. Among 91 patients not receiving oral anticoagulants, six had low protein S antigen levels and one had a low protein C antigen level. Among 50 patients receiving oral anticoagulant therapy, abnormally low ratios of protein S or C to other vitamin K-dependent factors were presented by one patient for protein S and five for protein C. Thus, heterozygous Type I protein S deficiency appeared in seven of 141 patients (5%) and heterozygous Type I protein C deficiency in six of 141 patients (4%). Eleven of thirteen deficient patients had recurrent venous thrombosis. In this group of 141 patients, 1% had an identifiable fibrinogen abnormality, 2% a plasminogen abnormality, and 3% an antithrombin III deficiency. Thus, among the known plasma protein deficiencies associated with venous thrombosis, protein S and protein C. deficiencies (9%) emerge as the leading identifiable associated abnormalities.

Download Full-text

Application of Two Neutral Mspl DNA Polymorphisms in the Analysis of Hereditary Protein C Deficiency

Thrombosis and Haemostasis ◽

10.1055/s-0038-1647293 ◽

1990 ◽

Vol 64 (02) ◽

pp. 239-244 ◽

Cited By ~ 8

Author(s):

P H Reitsma ◽

W te Lintel Hekkert ◽

E Koenhen ◽

P A van der Velden ◽

C F Allaart ◽

...

Keyword(s):

Protein C ◽

Stop Codon ◽

Normal Population ◽

Amino Acid Position ◽

Rare Allele ◽

Dna Polymorphisms ◽

Type I ◽

Protein C Deficiency ◽

Gene Deletions ◽

Allelic Frequencies

SummaryScreening of restriction erzyme digested DNA from normal and protein C deficient individuals with a variety of probes derived from the protein C locus has revealed the existence of two neutral MspI polymorphism. One polymorphism (MI), which is located ≈7 kb upstream of the protein C gene, has allelic frequencies of 69 and 31%, and was used to exclude extensive gene deletions as a likely cause of type I protein C deficiency in 50% of cases in a panel of 22 families. Furtherrnore, the same polymorphism has been used in 5 doubly affected individuals establishing compound heterozygosity in 3 of these.The second, intragenic, polymorphism (MII) has allelic frequencies of 99 and 1% in the normal population. The frequency of the rare allele of this RFLP was with 7% much higher in a panel of 22 Dutch families with protein C deficiency. Interestingly, in all three probands that were heterozygous for MII the rare allele of MII coincided with a point mutation that leads to a stop codon in amino acid position 306 of the protein C coding sequence. This mutation may account for 14% of the protein C deficient individuals in The Netherlands.

Download Full-text

Ectopic Transcript Analysis Indicates that Allelic Exclusion is an Important Cause of Type I Protein C Deficiency in Patients with Nonsense and Frameshift Mutations in the PROC Gene

Thrombosis and Haemostasis ◽

10.1055/s-0038-1650386 ◽

1996 ◽

Vol 75 (06) ◽

pp. 870-876 ◽

Cited By ~ 4

Author(s):

José Manuel Soria ◽

Lutz-Peter Berg ◽

Jordi Fontcuberta ◽

Vijay V Kakkar ◽

Xavier Estivill ◽

...

Keyword(s):

Splice Site ◽

Protein C ◽

Stop Codon ◽

Premature Stop Codon ◽

Allelic Exclusion ◽

Polymorphism Analysis ◽

Type I ◽

Protein C Deficiency ◽

Nonsense Mutations ◽

Stop Codons

SummaryNonsense mutations, deletions and splice site mutations are a common cause of type I protein C deficiency. Either directly or indirectly by altering the reading frame, these' lesions generate or may generate premature stop codons and could therefore be expected to result in premature termination of translation. In this study, the possibility that such mutations could instead exert their pathological effects at an earlier stage in the expression pathway, through “allelic exclusion” at the RNA level, was investigated. Protein C (PROC) mRNA was analysed in seven Spanish type I protein C deficient patients heterozygous for two nonsense mutations, a 7bp deletion, a 2bp insertion and three splice site mutations. Ectopic RNA transcripts from patient and control lymphocytes were analysed by RT-PCR and direct sequencing of amplified PROC cDNA fragments. The nonsense mutations and the deletion were absent from the cDNAs indicating that only mRNA derived from the normal allele had been expressed. Similarly for the splice site mutations, only normal PROC cDNAs were obtained. In one case, exclusion of the mutated allele could be confirmed by polymorphism analysis. In contrast to these six mutations, the 2 bp insertion was not associated with loss of mRNA from the mutated allele. In this case, cDNA analysis revealed the absence of 19 bases from the PROC mRNA consistent with the generation and utilization of a cryptic splice site 3’ to the site of mutation, which would result in a frameshift and a premature stop codon. It is concluded that allelic exclusion is a common causative mechanism in those cases of type I protein C deficiency which result from mutations that introduce premature stop codons

Download Full-text

The human beta fibrinogen promoter contains a hepatocyte nuclear factor 1-dependent interleukin-6-responsive element

Molecular and Cellular Biology ◽

10.1128/mcb.13.2.1183-1193.1993 ◽

1993 ◽

Vol 13 (2) ◽

pp. 1183-1193

Author(s):

J Dalmon ◽

M Laurent ◽

G Courtois

Keyword(s):

Binding Site ◽

Acute Phase ◽

Interleukin 6 ◽

Constitutive Expression ◽

Nuclear Proteins ◽

Functional Coupling ◽

Nuclear Factor ◽

Hepatocyte Nuclear Factor ◽

Tissue Specific ◽

Nuclear Factor 1

Acute-phase reactants are liver proteins whose synthesis is positively or negatively regulated during inflammation. The main mediators of this phenomenon are glucocorticoids and interleukin-6 (IL-6), a pleiotropic cytokine that also controls hematopoiesis. Functional analysis of several acute-phase reactant promoter regions has identified two major DNA motifs used by IL-6-regulated genes. The first one corresponds to a CTGG(G/A)AA sequence, and the other is a binding site for members of the C/EBP family of nuclear proteins. We have previously shown that the human beta fibrinogen (beta Fg) promoter contains an IL-6-responsive region, located between bp -150 and -67 (P. Huber, M. Laurent, and J. Dalmon, J. Biol. Chem. 265:5695-5701, 1990). In this study, using DNase I footprinting, mobility shift assays, and mutagenesis, we demonstrate that at least three subdomains of this region are necessary to observe a full response to IL-6. The most distal contains a CTGGGAA motif, and its mutation inhibits IL-6 stimulation. Another, which is able to interact with several distinct nuclear proteins, among them members of the C/EBP family, is dispensable for IL-6 induction but plays an important role in the constitutive expression of beta Fg. Finally, a proximal hepatocyte nuclear factor 1 binding site, already described as the major determinant of beta Fg tissue-specific expression, is also required for IL-6 stimulation. These results indicate a complex interplay between nuclear proteins within the beta Fg IL-6-responsive region and suggest a tight functional coupling between the tissue-specific and inducible elements.

Download Full-text