Switch to
| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
28
|
| pubmed:dateCreated |
1986-1-3
|
| pubmed:abstractText |
The characteristics of component activities in Co-eIF-2 (where eIF is eukaryotic initiation factor) protein complex have been studied. (i) At limiting concentrations, Co-eIF-2 promoted rapid GDP binding to eIF-2 and also GDP displacement from eIF-2 X GDP during ternary complex formation in the presence of GTP and Mg2+ (Co-eIF-2C activity) but did not significantly stimulate ternary complex formation by eIF-2. (ii) At higher concentrations, Co-eIF-2 significantly enhanced ternary complex formation by eIF-2 and also rendered the complex stable to aurintricarboxylic acid presumably as Co-eIF-2 became physically bound to the ternary complex (Co-eIF-2A activity). (iii) Ternary complex preformed in the presence of Co-eIF-2 and without Mg2+ dissociated upon subsequent addition of Mg2+ (Co-eIF-2B activity). This dissociation reaction was presumably due to loss of interaction of the Co-eIF-2A component in Co-eIF-2 with the ternary complex (reversal of Co-eIF-2A activity) as the complex became increasingly sensitive to aurintricarboxylic acid with increasing Mg2+ concentration. In another study, purified eIF-2 was freed of bound GDP by treatment with alkaline phosphatase and the characteristics of native and GDP-free eIF-2 were compared. (i) One mM Mg2+ inhibited (60%) ternary complex formation by native eIF-2 but not by GDP-free eIF-2. Addition of exogenous GDP rendered GDP-free eIF-2 sensitive to Mg2+ indicating that Mg2+ inhibition is due to eIF-2-bound GDP. (ii) In the presence of Mg2+, Co-eIF-2 stimulated similarly ternary and Met-tRNAf X 40 S X AUG complex formation by both native and GDP-free eIF-2. Such stimulatory activity in each case was strongly inhibited by prior phosphorylation of eIF-2 alpha subunit by heme-regulated translational inhibitor. (iii) Ternary complexes preformed using either native and GDP-free eIF-2 and excess Co-eIF-2A80 in the absence of Mg2+ did not form Met-tRNAf X 40 S X AUG complex. They required trace amounts of Co-eIF-2 for such activity.
|
| pubmed:grant | |
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Alkaline Phosphatase,
http://linkedlifedata.com/resource/pubmed/chemical/Aurintricarboxylic Acid,
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/Guanosine Diphosphate,
http://linkedlifedata.com/resource/pubmed/chemical/Guanosine Triphosphate,
http://linkedlifedata.com/resource/pubmed/chemical/Macromolecular Substances,
http://linkedlifedata.com/resource/pubmed/chemical/Magnesium,
http://linkedlifedata.com/resource/pubmed/chemical/Peptide Initiation Factors,
http://linkedlifedata.com/resource/pubmed/chemical/Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/RNA, Transfer, Amino Acyl,
http://linkedlifedata.com/resource/pubmed/chemical/RNA, Transfer, Met,
http://linkedlifedata.com/resource/pubmed/chemical/tRNA, formylmethionine-
|
| pubmed:status |
MEDLINE
|
| pubmed:month |
Dec
|
| pubmed:issn |
0021-9258
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
5
|
| pubmed:volume |
260
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
14976-81
|
| pubmed:dateRevised |
2007-11-14
|
| pubmed:meshHeading |
pubmed-meshheading:3851808-Alkaline Phosphatase,
pubmed-meshheading:3851808-Animals,
pubmed-meshheading:3851808-Aurintricarboxylic Acid,
pubmed-meshheading:3851808-Eukaryotic Initiation Factor-2,
pubmed-meshheading:3851808-Guanine Nucleotide Exchange Factors,
pubmed-meshheading:3851808-Guanosine Diphosphate,
pubmed-meshheading:3851808-Guanosine Triphosphate,
pubmed-meshheading:3851808-Kinetics,
pubmed-meshheading:3851808-Macromolecular Substances,
pubmed-meshheading:3851808-Magnesium,
pubmed-meshheading:3851808-Peptide Initiation Factors,
pubmed-meshheading:3851808-Protein Biosynthesis,
pubmed-meshheading:3851808-Proteins,
pubmed-meshheading:3851808-RNA, Transfer, Amino Acyl,
pubmed-meshheading:3851808-RNA, Transfer, Met,
pubmed-meshheading:3851808-Rabbits,
pubmed-meshheading:3851808-Reticulocytes
|
| pubmed:year |
1985
|
| pubmed:articleTitle |
Protein synthesis in rabbit reticulocytes. A study of the mechanism of Co-eIF-2 action.
|
| pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
|