| Autor: |
Garcia-Barrio, Minerva, Jinsheng Dong, Ufano, Sandra, Hinnebusch, Alan G. |
| Předmět: |
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| Zdroj: |
EMBO Journal; 4/15/2000, Vol. 19 Issue 8, p1887-1899, 13p |
| Abstrakt: |
Stimulation of GCN4 mRNA translation due to phosphorylation of the α-subunit of initiation factor 2 (eIF2) by its specific kinase, GCN2, requires binding of uncharged tRNA to a histidyl-tRNA synthetase (HisRS)-like domain in GCN2.GCN2 function in vivo also requires GCN1 and GCN20, but it was unknown whether these latter proteins act directly to promote the stimulation of GCN2 by uncharged tRNA. We found that the GCN1-GCN20 complex physically interacts with GCN2, binding to the N-terminus of the protein. Overexpression of N-terminal GCN2 segments had a dominant-negative phenotype that correlated with their ability to interact with GCN1-GCN20 and impede association between GCN1 and native GCN2. Consistently, this Gcn- phcnotypc was suppressed by overexpressing GCN2, GCNI-GCN20 or tRNAHis. The requirement for GCN1 was also reduced by overexpressing tRNAHis in a gcn1Δ strain. We conclude that binding of GCN1-GCN20 to GCN2 is required for its activation by uncharged tRNA. The homologous N-terminus of Drosophila GCN2 interacted with yeast GCN1-GCN20 and had a dominant Gcn- phenotype, suggesting evolutionary conservation of this interaction. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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