Linked Life Data

21280672

Source:http://linkedlifedata.com/resource/pubmed/id/21280672

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2011-4-1
pubmed:abstractText
The eukaryotic initiation factor 3 (eIF3) is an essential, highly conserved multiprotein complex that is a key component in the recruitment and assembly of the translation initiation machinery. To better understand the molecular function of eIF3, we examined its composition and phosphorylation status in Saccharomyces cerevisiae. The yeast eIF3 complex contains five core components: Rpg1, Nip1, Prt1, Tif34, and Tif35. 2-D LC-MS/MS analysis of affinity purified eIF3 complexes showed that several other initiation factors (Fun12, Tif5, Sui3, Pab1, Hcr1, and Sui1) and the casein kinase 2 complex (CK2) copurify. In Vivo metabolic labeling of proteins with (32)P revealed that Nip1 is phosphorylated. Using 2-D LC-MS/MS analysis of eIF3 complexes, we identified Prt1 phosphopeptides indicating phosphorylation at S22 and T707 and a Tif5 phosphopeptide with phosphorylation at T191. Additionally, we used immobilized metal affinity chromatography (IMAC) to enrich for eIF3 phosphopeptides and tandem mass spectrometry to identify phosphorylated residues. We found that three CK2 consensus sequences in Nip1 are phosphorylated: S98, S99, and S103. Using in vitro kinase assays, we showed that CK2 phophorylates Nip1 and that a synthetic Nip1 peptide containing S98, S99, and S103 competitively inhibits the reaction. Replacement of these three Nip1 serines with alanines causes a slow growth phenotype.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
1535-3907
pubmed:author
pubmed:issnType
Electronic
pubmed:day
1
pubmed:volume
10
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1481-94
pubmed:dateRevised
2011-9-22
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Assessing the components of the eIF3 complex and their phosphorylation status.
pubmed:affiliation
Department of Biochemisty, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-2363, United States.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural