GI domain-mediated association of the eukaryotic initiation factor 2α kinase GCN2 with its activator GCN1 is required for general amino acid control in budding yeast

Hiroyuki Kubota, Yoshiyuki Sakaki, Takashi Ito

Research output: Contribution to journalArticle

41 Citations (Scopus)


In response to the starvation of a single amino acid, the budding yeast Saccharomyces cerevisiae activates numerous genes involved in various amino acid biosynthetic pathways, all of which are under the control of transcription factor GCN4. This general amino acid control response is based on de-repressed translation of GCN4 mRNA, which is induced by the activation of the eIF2α kinase, GCN2. Although it is known that in vivo activation of GCN2 requires GCN1, the mode of GCN1 action remains to be elucidated at the molecular level. Here, we show that GCN2 interacts with GCN1 via the GI domain, a novel protein-binding module that occurs at the N terminus; mutations to conserved residues of this domain abolish its binding to GCN1. Furthermore, the yeast cells with GCN2 defective in interaction with GCN1 fail to display general control response. A similar phenotype is observed in cells overexpressing the GI domain of GCN2 or its target region on GCN1. Thus, GI domain-mediated association of GCN2 to GCN1 is required for general amino acid control. This finding provides the first insight into the molecular mechanism for the activation of GCN2 by GCN1.

Original languageEnglish
Pages (from-to)20243-20246
Number of pages4
JournalJournal of Biological Chemistry
Issue number27
Publication statusPublished - Jul 7 2000
Externally publishedYes


All Science Journal Classification (ASJC) codes

  • Biochemistry

Cite this