Budding Yeast GCN1 Binds the GI Domain to Activate the eIF2α Kinase GCN2

Hiroyuki Kubota, Kazuhisa Ota, Yoshiyuki Sakaki, Takashi Ito

研究成果: ジャーナルへの寄稿学術誌査読

42 被引用数 (Scopus)


When starved for a single amino acid, the budding yeast Saccharomyces cerevisiae activates the eukaryotic initiation factor 2α (eIF2α) kinase GCN2 in a GCN1-dependent manner. Phosphorylated eIF2α inhibits general translation but selectively derepresses the synthesis of the transcription factor GCN4, which leads to coordinated induction of genes involved in biosynthesis of various amino acids, a phenomenon called general control response. We recently demonstrated that this response requires binding of GCN1 to the GI domain occurring at the N terminus of GCN2 (Kubota, H., Sakaki, Y., and Ito, T. (2000) J. Biol. Chem. 275, 20243-20246). Here we provide the first evidence for the involvement of GCN1-GCN2 interaction in activation of GCN2 per se. We identified a C-terminal segment of GCN1 sufficient to bind the GI domain and used a novel dual bait two-hybrid method to identify mutations rendering GCN1 incapable of interacting with GCN2. The yeast bearing such an allele, gcn1-F2291L, fails to display derepression of GCN4 translation and hence general control response, as does a GI domain mutant, gcn2-Y74A, defective in association with GCN1. Furthermore, we demonstrated that phosphorylation of eIF2α is impaired in both mutants. Since GCN2 is the sole eIF2α kinase in yeast, these findings indicate a critical role of GCN1-GCN2 interaction in activation of the kinase in vivo.

ジャーナルJournal of Biological Chemistry
出版ステータス出版済み - 5月 18 2001

!!!All Science Journal Classification (ASJC) codes

  • 生化学
  • 分子生物学
  • 細胞生物学


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