Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P02794 (ferritin)
 17,525 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A technique employing ferritin-conjugated antibody has been developed to visualize specific protein-DNA complexes in the electron microscope and has been used to demonstrate the preferential binding of simian virus 40 (SV40) T antigen at or near the origin of replication of SV40 DNA, 0.67 fractional length clockwise from the EcoRI restriction endonuclease cleavage site. urified covalently closed supercoiled circles of SV40DNA were treated with partially purified T antigen and the complex was stabilized by crosslinking with glutaraldehyde. Hamster antiT antigen gamma-globulin, ferritin-labeled goat anti-hamster gamma-globulin, and glutaraldehyde were then added sequentially. The location of the bound ferritin cores was measured with respect to the EcoRI cleavage site and the orientation of the cores relative to the ends of the DNA was determined with respect to the locations of Escherichia coli DNA unwinding protein, which binds to covalently closed supercoiled SV40 DNA at either of two preferred sites, 0.46 or 0.90 fractional length clockwide from the EcoRI cleavage site.
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PMID:T antigen binds to simian virus 40 DNA at the origin of replication. 16 17

Estrogen administration to male Xenopus causes the cytoplasmic destabilization of the hepatic serum protein coding mRNAs, most notably, albumin, yet has little effect on mRNAs encoding intracellular proteins such as ferritin. This report describes an estrogen-inducible ribonuclease activity found in liver polysomes that degrades albumin mRNA 4 times faster in vitro than it degrades ferritin mRNA. This differential rate of degradation was observed upon incubation of polysome extract with free liver RNA, isolated liver mRNPs, or transcripts from plasmid vectors. A cleavage fragment consisting of a doublet of approximately 194 nucleotides in length was consistently observed upon digestion of transcripts for the full length or 5' half of albumin mRNA. The generation of this cleavage fragment was used as an assay to study properties of the polysome nuclease activity. The 194 doublet is produced by the action of a Mg(2+)-independent endonuclease. This distinguishes the Xenopus liver enzyme from the enzymes that degrade histone or c-myc mRNA in vitro. It is inactivated by 400 mM NaCl or heating at 90 degrees C, but not by placental ribonuclease inhibitor or N-ethylmaleimide. Finally, the polysomal nuclease activity does not degrade double-stranded RNA. We believe the estrogen-induced nuclease activity contains an enzyme(s) that may mediate hormone-regulated changes in mRNA stability in this tissue.
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PMID:Estrogen-induced ribonuclease activity in Xenopus liver. 193 72

Pleuropneumonia is an important disease of swine caused by Actinobacillus pleuropneumoniae. Putative virulence determinants include capsule, lipopolysaccharide, and cytotoxin. We studied the virulence and virulence determinants of 2 strains: CM5 and CM5A of serotype 1. Strain CM5 was isolated from a pig with pleuropneumonia and passaged once in vitro; strain CM5A was a substrain of CM5 passaged 70 times in vitro. Pigs challenge exposed to an aerosol of 1.3 x 10(7) colony-forming units of CM5/ml died within 30 hours; pigs challenge exposed to an aerosol of 1.6 x 10(8) colony-forming units of CM5A/ml survived. The average thickness of the capsular layer was 137 nm in strain CM5 and 53 nm in strain CM5A in bacteria treated with homologous antibody and examined by transmission electron microscopy. Similarly, capsular material binding polycationic ferritin was found in colonies of strain CM5, but not in strain CM5A. The ratio of hexosamine to protein in extracted capsule of CM5 was more than twice that of CM5A. The polyacrylamide gel electrophoretic profile of the lipopolysaccharide, outer membrane proteins, and whole cell proteins did not differ between the 2 strains. Also, the amount of cytotoxin or endotoxin produced by the 2 strains during the logarithmic growth phase was not different. The electrophoretic profile of restriction endonuclease digested DNA was similar, with the exception of bands in the 750- and 620-basepair regions. It was concluded that attenuation of strain CM5A during in vitro passage was a result of reduced capsule production and that encapsulation is an important virulence determinant of A pleuropneumoniae, serotype 1.
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PMID:Characterization of an attenuated strain of Actinobacillus pleuropneumoniae, serotype 1. 233 67

Patients with Hb SC disease were found to have microcytic and hyperchromic red cell indices despite mild reticulocytosis. Iron deficiency anemia was ruled out by the finding of normal serum ferritin levels. In order to determine whether the microcytosis was due to coexistent alpha-thalassemia, restriction endonuclease mapping was performed on genomic DNA extracted from peripheral blood leukocytes. Patients with Hb SC disease had microcytic indices despite the presence of a full complement of four alpha-genes (alpha alpha/alpha alpha), suggesting that the microcytosis may be due to cellular dehydration (or xerocytosis), since the mean corpuscular hemoglobin concentration in Hb SC disease patients was significantly higher than in controls. This possibility was investigated further by the determination of RBC cation content. RBC Na levels were similar in SC and normal red cells. Hb SC RBCs, however, had significantly reduced K levels. These findings show that RBC cation content, and thus cell water, is decreased in Hb SC disease. The decreased RBC K level in the presence of normal cellular Na concentration suggests selective K loss that is not due to inhibition of the Na K pump. Ouabain-insensitive K+ efflux was increased to four times normal in SC cells. Cell dehydration was confirmed by the demonstration of increased high-density RBCs on discontinuous Stractan density gradients and by osmotic gradient ektacytometry. Cellular dehydration and its sequelae were worse in CC erythrocytes and milder in AC cells than in Hb SC red cells. Taken together, these data indicate that in Hb SC disease the RBCs are severely dehydrated and typically microcytic and hyperchromic. Hb SC RBCs seem to be dehydrated due to selective K loss. These findings suggest a functional interrelationship between Hb SC, the red cell membrane, and cation regulation.
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PMID:The xerocytosis of Hb SC disease. 294 42

We have purified an approximately 60 kDa endoribonuclease from Xenopus liver polysomes with properties expected for a messenger RNase involved in the estrogen-regulated destabilization of serum protein mRNAs (Dompenciel et al., 1995, J Biol Chem 270:6108-6118). The present report describes the cloning of this protein and its identification as a novel member of the peroxidase gene family. This novel enzyme, named polysomal RNase 1, or PMR-1 has 57% sequence identity with myeloperoxidase, and like that protein, appears to be processed from a larger precursor. Unlike myeloperoxidase, however, PMR-1 lacks N-linked oligosaccharide, heme, and peroxidase activity. Western blot and immunoprecipitation experiments using epitope-specific antibodies to the derived protein sequence confirm the identity of the cloned cDNA to the protein originally isolated from polysomes. The 80 kDa pre-PMR-1 expressed in a recombinant baculovirus was not processed to the 60 kDa form in Sf9 cells and lacks RNase activity. However, the baculovirus-expressed mature 60-kDa form of the enzyme has RNase activity. The recombinant protein is an endonuclease that shows selectivity for albumin versus ferritin mRNA. While it does not cleave at consensus APyrUGA elements, recombinant PMR-1 generates the same minor cleavage products from albumin mRNA as PMR-1 purified from liver. Finally, we show estrogen induces only a small increase in the amount of PMR-1. This result is consistent with earlier data suggesting estrogen activates mRNA decay through a posttranslational pathway.
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PMID:A polysomal ribonuclease involved in the destabilization of albumin mRNA is a novel member of the peroxidase gene family. 984 52

Amplification of the region of the HFE gene that contains the c.845G-->A (C282Y) mutation is usually performed using one amplimer that binds to a sequence in intron 3 and another that binds to a sequence in intron 4. Previously, a mutation that interferes with efficient binding to the intron 4 site has been described. We now find that another common mutation in intron 3, IVS3 -48c-->g, prevents binding of the amplimer to that site. This polymorphism occurs at a gene frequency of 0.128 in the African-American population and at a frequency of only 0.006 in the European population. DNA samples heterozygous for the IVS3 -48c-->g polymorphism and C282Y were undistinguishable from samples homozygous for the C282Y mutation when they were examined by allele-specific oligonucleotide hybridization (ASOH) and showed only a weak normal band when examined by electrophoresis following restriction endonuclease digestion. Although the polymorphism occurs in a DNA sequence almost identical to the intron 3 splice donor site, we found no evidence of alternative splice forms. Moreover, serum iron, transferrin saturation, and serum ferritin levels were normal in subjects heterozygous for the polymorphism. It appears, therefore, that the main importance of this polymorphism is that it may lead to misdiagnosis of heterozygotes for the C282Y mutation as homozygotes. We therefore recommend exonic amplimers that avoid sites that contain polymorphisms and that can be multiplexed for detection of the c.187C-->G (H63D) and c.845G-->A (C282Y) mutations.
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PMID:A common intron 3 mutation (IVS3 -48c-->g) leads to misdiagnosis of the c.845G-->A (C282Y) HFE gene mutation. 1095 Sep 43

We report a method for detection of recurring side-chain patterns (DRESPAT) using an unbiased and automated graph theoretic approach. We first list all structural patterns as sub-graphs where the protein is represented as a graph. The patterns from proteins are compared pair-wise to detect patterns common to a protein pair based on content and geometry criteria. The recurring pattern is then detected using an automated search algorithm from the all-against-all pair-wise comparison data of proteins. Intra-protein pattern comparison data are used to enable detection of patterns recurring within a protein. A method has been proposed for empirical calculation of statistical significance of recurring pattern. The method was tested on 17 protein sets of varying size, composed of non-redundant representatives from SCOP superfamilies. Recurring patterns in serine proteases, cysteine proteases, lipases, cupredoxin, ferredoxin, ferritin, cytochrome c, aspartoyl proteases, peroxidases, phospholipase A2, endonuclease, SH3 domain, EF-hand and lectins show additional residues conserved in the vicinity of the known functional sites. On the basis of the recurring patterns in ferritin, EF-hand and lectins, we could separate proteins or domains that are structurally similar yet different in metal ion-binding characteristics. In addition, novel recurring patterns were observed in glutathione-S-transferase, phospholipase A2 and ferredoxin with potential structural/functional roles. The results are discussed in relation to the known functional sites in each family. Between 2000 and 50,000 patterns were enumerated from each protein with between ten and 500 patterns detected as common to an evolutionarily related protein pair. Our results show that unbiased extraction of functional site pattern is not feasible from an evolutionarily related protein pair but is feasible from protein sets comprising five or more proteins. The DRESPAT method does not require a user-defined pattern, size or location of the pattern and therefore, has the potential to uncover new functional sites in protein families.
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PMID:Functional sites in protein families uncovered via an objective and automated graph theoretic approach. 1258 52

Oppositely charged natural DNA and chitosan (CS) were assembled into (CS/DNA)(n) layer-by-layer films on electrode surface, and Ru(bpy)(3)(2+) (bpy = bipyridyl) in solution was used as electroactive catalyst to detect damage of DNA in the films after incubation of the films in ferritin/AA/H(2)O(2) solutions (AA = ascorbic acid). The mechanism of DNA damage caused by the ferritin/AA/H(2)O(2) system was similar to that of Fenton reaction, where the reaction of ferritin with AA would release some Fe(II) ions from ferritin and the following reaction between Fe(II) ions and H(2)O(2) would produce hydroxyl radical, which could induce DNA oxidative damage. This system provided an in vitro model to imitate the DNA damage indirectly induced by ferritin in real bio-systems. In addition, formamidopyrimidine DNA glycosylase (Fpg), a key endonuclease enzyme in repair of oxidatively damaged DNA, was used to amplify the DNA damage caused by ferritin/AA/H(2)O(2) system through conversion of oxidative purine bases into single-strand breaks. The high sensitivity of electrocatalytic method with Ru(bpy)(3)(2+) as the catalyst in detection of DNA damage and the magnification function of Fpg may provide a novel idea to detect natural DNA lesion sensitively.
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PMID:Electrochemical detection of natural DNA damage induced by ferritin/ascorbic acid/H2O2 system and amplification of DNA damage by endonuclease Fpg. 1963 6

Marine viruses shape microbial communities with the most genetic diversity in the sea by multiple genetic exchanges and infect multiple marine organisms. Here we provide proof from experimental infection that abalone shriveling syndrome-associated virus (AbSV) can cause abalone shriveling syndrome. This malady produces histological necrosis and abnormally modified macromolecules (hemocyanin and ferritin). The AbSV genome is a 34.952-kilobase circular double-stranded DNA, containing putative genes with similarity to bacteriophages, eukaryotic viruses, bacteria and endosymbionts. Of the 28 predicted open reading frames (ORFs), eight ORF-encoded proteins have identifiable functional homologues. The 4 ORF products correspond to a predicted terminase large subunit and an endonuclease in bacteriophage, and both an integrase and an exonuclease from bacteria. The other four proteins are homologous to an endosymbiont-derived helicase, primase, single-stranded binding (SSB) protein, and thymidylate kinase, individually. Additionally, AbSV exhibits a common gene arrangement similar to the majority of bacteriophages. Unique to AbSV, the viral genome also contains genes associated with bacterial outer membrane proteins and may lack the structural protein-encoding ORFs. Genomic characterization of AbSV indicates that it may represent a transitional form of microbial evolution from viruses to bacteria.
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PMID:A bacteriophage-related chimeric marine virus infecting abalone. 2107 76