Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

HFE is a class I major histocompatibility complex (MHC)-related protein that is mutated in patients with the iron storage disease hereditary hemochromatosis. HFE binds tightly to transferrin receptor (TfR), the receptor that mediates uptake of iron-loaded transferrin. The binding affinities for TfR of HFE mutants, designed using the HFE crystal structure, were measured using biosensor assays. The results allow localization of the TfR binding site on HFE to the C-terminal portion of the alpha1 domain helix and an adjacent loop, a region distinct from the ligand binding sites on class I MHC and related proteins. A biosensor-derived pH-dependent affinity profile for the HFE-TfR interaction is discussed in terms of HFE's hypothesized role in intracellular trafficking.
J Mol Biol 1999 Jun 18
PMID:The transferrin receptor binding site on HFE, the class I MHC-related protein mutated in hereditary hemochromatosis. 1036 85

Recently a candidate gene for hereditary hemo-chromatosis, HFE, was identified. The finding raises the possibility for genetic testing to provide earlier detection and more complete genotypic evaluation of hemochromatosis affected individuals. We determined the frequency of the HFE polymorphisms, C282Y and H63D, in a randomly selected multi-ethnic control population for establishment of a hemochromatosis genetic testing program. Prevalence was determined by PCR amplification and restriction enzyme digestion of HFE in 100 Caucasians, 100 Hispanics, and 56 African Americans. Heterozygosity for C282Y was detected in 8% of Caucasians, 3% of Hispanics, and 2% of African Americans. Homozygosity for C282Y was detected in 1% of Caucasians. Heterozygosity for H63D was detected in 24% of Caucasians, 15% Hispanics, and 3.5% of African Americans. Homozygosity for H63D was present in 4% of Caucasians and 1% of Hispanics. One Hispanic case was double heterozygous for C282Y and H63D. These results indicate the highest prevalence of C282Y and H63D in the Caucasian population. Additionally, we demonstrate C282Y and H63D polymorphisms in our Hispanic and African American populations, groups in which prevalence rates remain less defined. Our results support the need for thorough interpretation of genetic results for hereditary hemochromatosis in various ethnic populations.
Int J Mol Med 1999 Oct
PMID:Prevalence of the C282Y and H63D polymorphisms in a multi-ethnic control population. 1049 80

Universal screening for hereditary hemochromatosis (HH) has been proposed by many experts, with understandable enthusiasm: HH can cause fatal complications, which are preventable with early treatment. The disorder involves excess iron accumulation that can result in tissue iron overload, with secondary cirrhosis, diabetes, heart failure, impotence and arthritis. These complications are preceded by years of iron accumulation, and most are believed to be preventable by removal of excess iron by phlebotomy. Thus, early identification and treatment - the quintessential functions of health screening - seem to make sense for HH. However, the available screening tests are imperfect. While they can identify many persons at increased risk from HH, the proportion that will develop serious clinical manifestations related to iron overload is not known with certainty. DNA-based tests do not provide a simple resolution to these questions.
Mol Med Today 1999 Oct
PMID:Screening for hereditary hemochromatosis: are DNA-based tests the answer? 1049 10

HFE is a class I major histocompatibility complex (MHC)-related protein that is mutated in patients with the iron overload disease hereditary hemochromatosis. HFE binds to transferrin receptor (TfR), the receptor used by cells to obtain iron in the form of diferric transferrin (Fe-Tf). Previous studies demonstrated that HFE and Fe-Tf can bind simultaneously to TfR to form a ternary complex, and that membrane-bound or soluble HFE binding to cell surface TfR results in a reduction in the affinity of TfR for Fe-Tf. We studied the inhibition by soluble HFE of the interaction between soluble TfR and Fe-Tf using radioactivity-based and biosensor-based assays. The results demonstrate that HFE inhibits the TfR:Fe-Tf interaction by binding at or near the Fe-Tf binding site on TfR, and that the Fe-Tf:TfR:HFE ternary complex consists of one Fe-Tf and one HFE bound to a TfR homodimer.
J Mol Biol 1999 Nov 19
PMID:The hemochromatosis protein HFE competes with transferrin for binding to the transferrin receptor. 1055 42

An increasing number of studies demonstrate a lack of phenotypic expression in subjects found to be homozygous for the common hereditary hemochromatosis (HH) mutation, C282Y. In this study the impact of possible overestimation of C282Y homozygosity, as a consequence of a MseI polymorphism identified in intron 4 of the HFE gene, was investigated in South African subjects. Utilization of a modified polymerase chain reaction (PCR)-based assay highlighted the potential implications with respect to genotype/phenotype correlation studies, particularly in the general population. Mistyping rather than lack of disease association provides a plausible explanation for the phenomenon of C282Y homozygosity without iron overload. Reassessment of C282Y mutation status in such cases may result in justified population screening in HH.
Blood Cells Mol Dis
PMID:Significance of linkage disequilibrium between mutation C282Y and a MseI polymorphism in population screening and DNA diagnosis of hemochromatosis. 1057 50

Two amino acid variants in the HFE gene, C282Y and H63D, have been reported in most cases of hereditary hemochromatosis. A recently discovered novel amino acid variant of HFE, namely S65C, has been implicated to be responsible for a mild form of iron overload. We determined genotypes of the HFE S65C variant in 230 voluntary blood donors with a transferrin saturation >45%, who did not carry the HFE C282Y variant. The control group consisted of 248 first time blood donors who had a transferrin saturation < 45%. We also determined genotypes of the HFE H63D variant in the two groups. For the HFE S65C variant, the frequency of the HFE C65 allele was 1. 7% and 2.2% in the high and low transferrin saturation groups, respectively (p = 0.65). In contrast, for the HFE H63D variant, the frequency of the HFE D63 allele was 24.8% and 14.7% in the high and low transferrin saturation groups, respectively (p = 0.0009). This study demonstrates no association of the HFE C65 allele with the phenotype of high transferrin saturation. The results do not support the use of DNA genotyping for the HFE S65C mutation in population screening studies for hemochromatosis.
Blood Cells Mol Dis
PMID:HFE S65C variant is not associated with increased transferrin saturation in voluntary blood donors. 1066 Apr 84

The discovery of the C282Y and H63D point mutations in the hereditary hemochromatosis-associated HFE gene allows us to study the molecular basis of congenital and acquired iron overload disorders. In hereditary hemochromatosis an increased frequency of the C282Y and, to a lesser extent, of the H63D mutations has been established, but their role in other conditions associated with iron overload and their prevalence in the normal population are still under investigation. We sought to determine the presence of such mutations, and their possible involvement in the multi-step neoplastic transformation of the hepatocytes, in patients diagnosed with hepatocellular carcinoma, a frequent complication of iron-induced liver cirrhosis occurring in untreated hereditary hemochromatosis subjects. The frequency of the C282Y and H63D mutations was determined in DNA from 12 patients with hepatocellular carcinoma and with no clinical signs of hereditary hemochromatosis. The frequency of the mutations was also determined in 130 normal subjects. A germline C282Y mutation was found in none of the hepatocellular carcinoma patients; the frequency of the H63D mutation was not increased, compared to the 130 controls. The allele frequencies of the C282Y and H63D mutations in the normal population were 0.042 and 0.185, respectively. In conclusion, we suggest that the hereditary hemochromatosis-related mutations of the HFE gene do not play a significant role in the pathogenesis of hepatocellular carcinoma.
Blood Cells Mol Dis
PMID:Mutations of the HFE gene and the risk of hepatocellular carcinoma. 1066 Apr 82

In 1996 two mutations in Hfe, the gene affected in hereditary hemochromatosis, were identified as C282Y (c.845G. A) and H63D (c.187C. G). Immunohistochemical studies have localized the protein product of Hfe to the deep crypts of the duodenum, the maximum site of iron absorption. To date, there are no published data on the cellular location and regulation of Hfe in patients with hemochromatosis who are homozygous for C282Y. The aim of this study was to identify the cellular localization of Hfe in genotyped individuals and to study possible regulation of this protein by the mutations described in the Hfe gene locus and iron deficiency. Duodenal biopsy specimens and serum for iron, ferritin, and transferrin saturation were taken from controls (n = 10) and patients with hereditary hemochromatosis (n = 10) and iron deficiency anemia (n = 10). All participants were genotyped for C282Y and H63D mutations. Expression of Hfe in the duodenum was demonstrated by immunohistochemistry. Hfe was expressed in the deep crypts of the duodenum in all three groups in a perinuclear fashion. Hfe staining was weaker in the hemochromatosis and iron deficiency patients (mean transferrin saturation 69.6%, SD 23% and 15%, SD 11%, respectively) when compared to controls (mean transferrin saturation 33.1%, SD 15%). There was no difference in the intensity of Hfe staining within the hemochromatosis group who were iron overloaded when compared to their iron-depleted counterparts. In summary, Hfe is expressed strongly in the deep crypts of the small intestine of normal subjects. Homozygosity for C282Y and conditions of iron deficiency result in a downregulation of Hfe. Furthermore, Hfe is not regulated by therapeutic iron depletion in patients with hemochromatosis who are homozygous for the C282Y mutation.
Blood Cells Mol Dis 2000 Feb
PMID:Immunohistochemistry of the Hfe protein in patients with hereditary hemochromatosis, iron deficiency anemia, and normal controls. 1077 70

Iron absorption by the duodenal mucosa is initiated by uptake of ferrous Fe(II) iron across the brush border membrane and culminates in transfer of the metal across the basolateral membrane to the portal vein circulation by an unknown mechanism. We describe here the isolation and characterization of a novel cDNA (Ireg1) encoding a duodenal protein that is localized to the basolateral membrane of polarized epithelial cells. Ireg1 mRNA and protein expression are increased under conditions of increased iron absorption, and the 5' UTR of the Ireg1 mRNA contains a functional iron-responsive element (IRE). IREG1 stimulates iron efflux following expression in Xenopus oocytes. We conclude that IREG1 represents the long-sought duodenal iron export protein and is upregulated in the iron overload disease, hereditary hemochromatosis.
Mol Cell 2000 Feb
PMID:A novel duodenal iron-regulated transporter, IREG1, implicated in the basolateral transfer of iron to the circulation. 1088 71

Hereditary hemochromatosis (HH) is common among Caucasians; reported disease frequencies vary from 0.3 to 0.8%. Identification of a candidate HFE gene in 1996 was soon followed by the description of two ancestral mutations, i.e., c.845G-->A (C282Y) and c.187C-->G (H63D). To these was recently added the mutation S65C, which may represent a simple polymorphism. The incidence of HH in Greece is unknown but clinical cases are rare. Also unknown is the carrier frequency of the two mutant alleles. A first estimate of the latter is given in the present report. It is based on data from the genetic analysis of 10 unrelated patients of Greek origin who were referred to our center for genotyping and 158 unselected male blood donors. The allele frequencies for the C282Y and H63D mutations were 0.003 and 0.145, respectively. The C282Y allele was detected in 50% of HH patients. This is considerably lower than the frequencies reported for HH patients in the U.S.A. (82%) and France (91 %) and closer to that reported in Italy (64%). Five patients did not carry any known HFE mutation; three may represent cases of juvenile hemochromatosis, given their early onset with iron overload, hypogonadism, and heart disease. We suggest that genetic heterogeneity is more prominent in Southern Europe. It is also possible that the penetrance of the responsible genes is different across the Mediterranean.
Blood Cells Mol Dis 2000 Apr
PMID:Hereditary hemochromatosis: HFE mutation analysis in Greeks reveals genetic heterogeneity. 1100 26


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