Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
46
pubmed:dateCreated
1999-12-20
pubmed:abstractText
Phosphorylation of the serine 51 residue in the alpha-subunit of translational initiation factor 2 in eukaryotes (eIF2 alpha) impairs protein synthesis presumably by sequestering eIF2B, a rate-limiting pentameric guanine nucleotide exchange protein which catalyzes the exchange of GTP for GDP in the eIF2-GDP binary complex. To further understand the importance of eIF2 alpha phosphorylation in the interaction between eIF2 alpha(P) and eIF2B proteins and thereby the regulation of eIF2B activity, we expressed the wild type (wt) and a mutant eIF2 alpha in which the serine 48 residue was replaced with alanine (48A mutant) in the baculovirus system. The findings reveal that the expression of both of these recombinant subunits was very efficient (15-20% of the total protein) and both proteins were recognized by an eIF2 alpha monoclonal antibody and were phosphorylated to the same extent by reticulocyte eIF2 alpha kinases. However, partially purified recombinant subunits (wt or 48A mutant) were not phosphorylated as efficiently as the eIF2 alpha subunit present in the purified reticulocyte trimeric eIF2 complex and were also found to inhibit the phosphorylation of eIF2 alpha of the trimeric complex. Furthermore, the extents of inhibition of eIF2B activity and formation of the eIF2 alpha(P)-eIF2B complex that occurs due to eIF2 alpha phosphorylation in poly(IC)-treated rabbit reticulocyte lysates were decreased significantly in the presence of insect cell extracts expressing the 48A mutant eIF2 alpha compared to those for wt. These findings support the hypothesis that the serine 48 residue is required for high-affinity interaction between eIF2 alpha(P) and eIF2B.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
16
pubmed:volume
38
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
15398-405
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:10563826-Amino Acid Substitution, pubmed-meshheading:10563826-Animals, pubmed-meshheading:10563826-Antibodies, Monoclonal, pubmed-meshheading:10563826-Binding Sites, pubmed-meshheading:10563826-Blotting, Western, pubmed-meshheading:10563826-Cell Fractionation, pubmed-meshheading:10563826-Eukaryotic Initiation Factor-2, pubmed-meshheading:10563826-Eukaryotic Initiation Factor-2B, pubmed-meshheading:10563826-Genetic Vectors, pubmed-meshheading:10563826-Humans, pubmed-meshheading:10563826-Macromolecular Substances, pubmed-meshheading:10563826-Nucleopolyhedrovirus, pubmed-meshheading:10563826-Phosphorylation, pubmed-meshheading:10563826-Poly I-C, pubmed-meshheading:10563826-Recombinant Proteins, pubmed-meshheading:10563826-Reticulocytes, pubmed-meshheading:10563826-Serine, pubmed-meshheading:10563826-Spodoptera, pubmed-meshheading:10563826-Transfection
pubmed:year
1999
pubmed:articleTitle
Serine 48 in initiation factor 2 alpha (eIF2 alpha) is required for high-affinity interaction between eIF2 alpha(P) and eIF2B.
pubmed:affiliation
Department of Biochemistry, University of Hyderabad, Andhra Pradesh, India.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't