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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
3
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pubmed:dateCreated |
1993-6-29
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pubmed:abstractText |
Iron is a required nutrient which, at high concentrations, can peroxidize cell lipids and other cellular components. To prevent excess iron from damaging cells, it is stored in ferritin, which consists of a shell of protein subunits of two related types, H (heavy) and L (light), surrounding a cavity in which the iron can be deposited. In order to prepare for a rapid increase in ferritin in response to a rise in cellular iron, a large number of dormant ferritin mRNAs are accumulated in the cytoplasm. These can be rapidly activated to yield a large population of ferritin subunits. Regulation is achieved through a 28-nucleotide "stem-and-loop" structure near the beginning of the H- and L-ferritin mRNAs. When this structure is associated with a binding protein (iron regulatory element binding protein, IRE-BP), translation of the ferritin mRNA cannot proceed. However, when intracellular iron accumulates, IRE-BP releases its hold and translation of the mRNA then takes place. IRE-BP has been identified as a cytosolic form of aconitase, containing several fourfold iron-sulfur clusters. Within each cluster one iron atom is labile; this may be the mechanism by which IRE-BP responds to intracellular iron levels. Finally, transcription of the L- and H-genes shows that L is preferentially transcribed in response to increased iron intake, whereas H responds to cell differentiation and other factors. More work is needed to define independent transcription of the individual genes, including regulation of components other than the 28-nucleotide segment.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Ferritins,
http://linkedlifedata.com/resource/pubmed/chemical/Iron,
http://linkedlifedata.com/resource/pubmed/chemical/Iron-Regulatory Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/RNA, Messenger,
http://linkedlifedata.com/resource/pubmed/chemical/RNA-Binding Proteins
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pubmed:status |
MEDLINE
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pubmed:month |
Mar
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pubmed:issn |
0029-6643
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
51
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
65-73
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:8502427-Animals,
pubmed-meshheading:8502427-Base Sequence,
pubmed-meshheading:8502427-Ferritins,
pubmed-meshheading:8502427-Gene Expression Regulation,
pubmed-meshheading:8502427-Humans,
pubmed-meshheading:8502427-Iron,
pubmed-meshheading:8502427-Iron-Regulatory Proteins,
pubmed-meshheading:8502427-Molecular Sequence Data,
pubmed-meshheading:8502427-RNA, Messenger,
pubmed-meshheading:8502427-RNA-Binding Proteins
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pubmed:year |
1993
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pubmed:articleTitle |
The ferritin genes: their response to iron status.
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pubmed:affiliation |
USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111.
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pubmed:publicationType |
Journal Article,
Review
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