Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1989-2-6
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.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
23
pubmed:volume
1007
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
55-60
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Phosphorylation and guanine nucleotide exchange on polypeptide chain initiation factor-2 from Artemia embryos.
pubmed:affiliation
Centro de Biología Molecular, Consejo Superior de Investigaciones Científicas, Madrid, Spain.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't