Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1994-7-1
pubmed:abstractText
The iron-responsive element-binding protein (IRE-BP) has been defined and identified as an RNA-binding protein found in iron-deprived eukaryotic cells. IRE-BP binds to stem-loop structures, iron-responsive elements (IREs), which are located in the untranslated regions of the mRNAs for several genes including ferritin, and the transferrin receptor. When bound, IRE-BP prevents ferritin translation and stabilizes the transferrin receptor transcript. When cells are iron replete, an iron-sulfur cluster is ligated to the IRE-BP, the protein loses RNA binding properties, and it acquires aconitase activity. Cytosolic aconitase from liver can be converted into the IRE-BP by oxidative removal of its Fe-S cluster. We describe here overexpression of IRE-BP in baculovirus-infected insect cells which yields IRE-BP devoid of an iron-sulfur cluster. We describe a one-step purification of the IRE-BP and a quantitative analysis of Fe, S2-, S0, protein, and enzyme activity on IRE-BP, as obtained in cell lysates, after purification, and after reconstitution to active aconitase. On the average not more than 3% of the over-expressed purified protein contained an intact Fe-S cluster, and it was demonstrated that that cluster was not lost during purification. Scatchard analysis of RNA-binding data was compatible with a single high-affinity RNA-binding form of the IRE-BP. Active aconitase could be reconstituted from the purified IRE-BP obtained from the expression system by addition of iron, thiol, and sulfide, and the characteristic epr spectrum of the 3Fe form of cytosolic aconitase was obtained after ferricyanide oxidation of the reconstituted material.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0003-9861
pubmed:author
pubmed:issnType
Print
pubmed:volume
311
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
517-22
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:8203918-Animals, pubmed-meshheading:8203918-Baculoviridae, pubmed-meshheading:8203918-Base Sequence, pubmed-meshheading:8203918-Binding Sites, pubmed-meshheading:8203918-Cloning, Molecular, pubmed-meshheading:8203918-Electron Spin Resonance Spectroscopy, pubmed-meshheading:8203918-Electrophoresis, Polyacrylamide Gel, pubmed-meshheading:8203918-Ferritins, pubmed-meshheading:8203918-Genetic Vectors, pubmed-meshheading:8203918-Humans, pubmed-meshheading:8203918-Insects, pubmed-meshheading:8203918-Iron-Regulatory Proteins, pubmed-meshheading:8203918-Iron-Sulfur Proteins, pubmed-meshheading:8203918-Kinetics, pubmed-meshheading:8203918-Molecular Sequence Data, pubmed-meshheading:8203918-Open Reading Frames, pubmed-meshheading:8203918-RNA, Messenger, pubmed-meshheading:8203918-RNA-Binding Proteins, pubmed-meshheading:8203918-Recombinant Proteins, pubmed-meshheading:8203918-Transcription, Genetic, pubmed-meshheading:8203918-Transfection
pubmed:year
1994
pubmed:articleTitle
Overexpression of iron-responsive element-binding protein and its analytical characterization as the RNA-binding form, devoid of an iron-sulfur cluster.
pubmed:affiliation
National Institutes of Health, National Institute of Child Health and Human Development, Bethesda, Maryland 20892.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S.