Linked Life Data

15377664

Source:http://linkedlifedata.com/resource/pubmed/id/15377664

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
48
pubmed:dateCreated
2004-11-23
pubmed:abstractText
The carboxyl-terminal domain (CTD) of eukaryotic initiation factor (eIF) 5 interacts with eIF1, eIF2beta, and eIF3c, thereby mediating formation of the multifactor complex (MFC), an important intermediate for the 43 S preinitiation complex assembly. Here we demonstrate in vitro formation of a nearly stoichiometric quaternary complex containing eIF1 and the minimal segments of eIF2beta, eIF3c, and eIF5. In vivo, overexpression of eIF2 and tRNA(Met)(i) suppresses the temperature-sensitive phenotype of tif5-7A altering eIF5-CTD by increasing interaction of the mutant eIF5 with eIF2 by mass action and restoring its defective interaction with eIF3. By contrast, overexpression of eIF1 exacerbated the tif5-7A phenotype because eIF1 forms unusual inhibitory complexes with a hyperstoichiometric amount of eIF1. Formation of such complexes leads to increased GCN4 translation, independent of eIF2 phosphorylation (general control derepressed or Gcd(-) phenotype). We also provide biochemical evidence indicating that the association of eIF5-CTD with eIF2beta strongly enhances its binding to eIF3c. Our results suggest strongly that MFC formation is an ordered event involving specific enhancement of eIF5-CTD binding to eIF3 on its binding to eIF2beta. We propose that the primary function of eIF5-CTD is to serve as an assembly guide by rapidly promoting stoichiometric MFC assembly with the aid of eIF2 while excluding formation of nonfunctional complexes.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
26
pubmed:volume
279
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
49644-55
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Physical association of eukaryotic initiation factor (eIF) 5 carboxyl-terminal domain with the lysine-rich eIF2beta segment strongly enhances its binding to eIF3.
pubmed:affiliation
Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, Kansas 66506, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.