Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The amino acid code and surrounding regions in the bovine ferrochelatase gene were amplified by a combination of reverse transcriptase PCR and vectorette PCR and sequenced. The bovine code was 86% homologous to the human ferrochelatase code but was altered at a position corresponding to the presumed human initiator codon.
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PMID:The coding sequence of the bovine ferrochelatase gene. 764 Feb 90

Ferrochelatase (FC; heme synthetase, EC 4.99.1.1.) catalyses the synthesis of heme from protoporphyrin IX, the final step in the heme synthetic pathway. The hereditary deficiency of this enzyme gives rise to erythropoietic protoporphyria (EPP). We developed a rapid, non-radioactive means of measuring human FC mRNA levels in the EPP patients. It is based on the reverse transcriptase-polymerase chain reaction (RT-PCR) performed on the RNA obtained from peripheral blood. The amplified DNA was detected by agarose gel electrophoresis with ethidium bromide staining and the fluorescent intensity was measured by scanning densitometry applied directly to Polaroid 665 negative film. The relative expression level of FC mRNA, compared with that of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) mRNA, was estimated at several points in the exponential phase of PCR cycles or at a point in the exponential phase of PCR performed on serially diluted the cDNA samples. The estimate of the FC mRNA by this method correlated well with the level of the FC mRNA measured by Northern blotting in the EB virus-transformed lymphocytes of the same patients. The level of the FC mRNA appeared to vary among the patients in whom a decreased level of enzymatic activity was indicated.
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PMID:Quantitative analysis of ferrochelatase mRNA in blood cells of erythropoietic protoporphyria patients. 886 37

Protoporphyria is a genetic disorder in which a deficiency of mitochondrial ferrochelatase activity causes accumulation of protoporphyrin that produces severe liver damage in some patients. In this study, mutations of the ferrochelatase gene were examined in eight unrelated patients who had liver transplantation. RNA was prepared from liver and/ or lymphoblasts, and specific reverse transcriptase-nested polymerase chain reactions amplified and sequenced ferrochelatase cDNAs. Products shorter than normal resulted from an exon 3 deletion in three patients, exon 10 deletion in two, exon 2 deletion in one, and deletion of five nucleotides in exon 5 in one. Sequence of normal-size products revealed no other mutations. Western blot showed a reduced quantity of normal-size ferrochelatase protein in protoporphyria liver compared with normal liver (19-51%, mean 32% of normal). Levels of the mitochondrial protein F1-ATPase beta-subunit were not decreased to a similar degree. Liver ferrochelatase activity was reduced more than could be explained by the decrease in ferrochelatase protein (4-20%, mean 9% of normal). These results establish genetic heterogeneity in the most severe phenotype of protoporphyria. However, the gene mutations found share the property of causing a major structural alteration in the ferrochelatase protein.
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PMID:Molecular defects in ferrochelatase in patients with protoporphyria requiring liver transplantation. 964 63

Protoporphyria is a disease characterized by a deficiency in ferrochelatase, the terminal enzyme in the heme biosynthetic pathway, which catalyzes the chelation of iron and protoporphyrin to form heme. Clinical symptoms arise from an accumulation of protoporphyrin behind the partial enzyme block and include photosensitivity and sometimes hepatobiliary disease. Protoporphyria is described as an dominant disease, yet patients exhibit decreased ferrochelatase activities of 15-30% of normal, not 50% as might be expected. Missense, nonsense, and splicing mutations have been identified in ferrochelatase cDNA from protoporphyric patients. In this study we introduce an exon 10 deletion, an analogous mutation to that described in some protoporphyric patients, into the mouse embryonic stem (ES) cell genome via homologous recombination. Targeted ES cells were confirmed by Southern blot analysis. Expression of wild-type and exon 10-deleted mRNA was demonstrated by reverse transcriptase-polymerase chain reaction (RT-PCR) and cDNA sequencing. Ferrochelatase levels were analyzed by immunoblotting. Ferrochelatase activity was measured by the chelation of zinc and mesoporphyrin, and by the decrease in protoporphyrin accumulation after adding delta-aminolevulinic acid. In the exon 10 +/- ES cells there is expression of both wild-type and exon 10-deleted mRNA, a 50% decrease in cross-reactive material with an anti-ferrochelatase antibody, and an approximate 50% decrease in ferrochelatase activity compared to wild-type ES cells. Therefore, an exon 10 deletion alone is insufficient to decrease ferrochelatase activity to the levels in protoporphyric patients. This suggests that requirement of an additional mutation to decrease the expression of the wild-type allele.
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PMID:Targeted disruption of the mouse ferrochelatase gene producing an exon 10 deletion. 998 56

Hemes and heme proteins are vital components of essentially every cell of virtually every eukaryote organism. Previously, we demonstrated accumulation of the heme precursor protoporphyrin-IX (PpIX) in gastrointestinal tumor tissues. To elucidate the mechanisms of PpIX accumulation by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), we studied expression of the relevant enzymes of the heme synthetic pathway. Here, we describe a significant down-regulation of ferrochelatase (FECH) mRNA expression in gastric, colonic, and rectal carcinomas. Accordingly, in an in vitro model of several carcinoma cell lines, ferrochelatase down-regulation and loss of enzymatic activity corresponded with an enhanced PpIX-dependent fluorescence. Direct detection of PpIX in minute amounts was achieved by a specifically developed pulsed solid-state laser dual delay fluorimetry setup. Silencing of FECH using small interfering RNA (siRNA) technology led to a maximum 50-fold increased PpIX accumulation, imageable by a specifically adapted two-photon microscopy unit. Our results show that in malignant tissue a transcriptional down-regulation of FECH occurs, which causes endogenous PpIX accumulation. Furthermore, accumulation of intracellular PpIX because of FECH siRNA silencing provides a small-molecule-based approach to molecular imaging and molecular therapy.
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PMID:Silencing of human ferrochelatase causes abundant protoporphyrin-IX accumulation in colon cancer. 1787 5