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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
1
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pubmed:dateCreated |
1989-2-6
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pubmed:abstractText |
Eukaryotic initiation factor-2 (eIF-2) from Artemia embryos is able to exchange guanine nucleotides at the same rate in the presence or absence of Mg2+ when the reaction is carried out with either purified eIF-2 at 30 degrees C or less purified preparations at any temperature (10-30 degrees C). No exchange factor appears to catalyze this reaction. However, with purified eIF-2 at lower temperatures (10 degrees C) the exchange is clearly impaired by Mg2+ and this impairment is overcome by the guanine nucleotide exchange factor (GEF) of rabbit reticulocytes. Thus, Artemia eIF-2 is able to exchange guanine nucleotides by two alternative mechanisms that may reflect two states of the protein. Phosphorylation of the eIF-2 alpha subunit by the heme-controlled inhibitor (HCI) of rabbit reticulocytes abolishes the GEF-dependent reaction, but has no effect on the factor-independent one. The search for eIF-2 alpha kinases in Artemia embryo led to the detection of only one such enzyme, which was identified as a casein kinase type II. None of the exchange reactions is affected by the phosphorylation of the eIF-2 alpha subunit by this kinase, suggesting that, irrespective of the kind of mechanism for guanine nucleotide exchange that is actually operating in Artemia, it might not be a target for regulation by eIF-2 alpha phosphorylation.
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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/Casein Kinases,
http://linkedlifedata.com/resource/pubmed/chemical/Eukaryotic Initiation Factor-2,
http://linkedlifedata.com/resource/pubmed/chemical/Guanine Nucleotide Exchange Factors,
http://linkedlifedata.com/resource/pubmed/chemical/Guanine Nucleotides,
http://linkedlifedata.com/resource/pubmed/chemical/Hydrochloric Acid,
http://linkedlifedata.com/resource/pubmed/chemical/Magnesium,
http://linkedlifedata.com/resource/pubmed/chemical/Peptide Initiation Factors,
http://linkedlifedata.com/resource/pubmed/chemical/Protein Kinases,
http://linkedlifedata.com/resource/pubmed/chemical/Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/eIF-2 Kinase
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pubmed:status |
MEDLINE
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pubmed:month |
Jan
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pubmed:issn |
0006-3002
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
23
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pubmed:volume |
1007
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
55-60
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pubmed:dateRevised |
2009-11-19
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pubmed:meshHeading |
pubmed-meshheading:2909242-Animals,
pubmed-meshheading:2909242-Artemia,
pubmed-meshheading:2909242-Casein Kinases,
pubmed-meshheading:2909242-Eukaryotic Initiation Factor-2,
pubmed-meshheading:2909242-Guanine Nucleotide Exchange Factors,
pubmed-meshheading:2909242-Guanine Nucleotides,
pubmed-meshheading:2909242-Hydrochloric Acid,
pubmed-meshheading:2909242-Magnesium,
pubmed-meshheading:2909242-Peptide Initiation Factors,
pubmed-meshheading:2909242-Phosphorylation,
pubmed-meshheading:2909242-Protein Kinases,
pubmed-meshheading:2909242-Proteins,
pubmed-meshheading:2909242-Rabbits,
pubmed-meshheading:2909242-Temperature,
pubmed-meshheading:2909242-eIF-2 Kinase
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pubmed:year |
1989
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pubmed:articleTitle |
Phosphorylation and guanine nucleotide exchange on polypeptide chain initiation factor-2 from Artemia embryos.
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pubmed:affiliation |
Centro de Biología Molecular, Consejo Superior de Investigaciones Científicas, Madrid, Spain.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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