The Inhibition of Protein Translation Mediated by AtGCN1 is Essential for Cold Tolerance in Arabidopsis thaliana
Linjuan Wang, Houhua Li, Chunzhao Zhao, Shengfei Li, Lingyao Kong, Wenwu Wu, Weisheng Kong, Yan Liu, Yuanyuan Wei, Jian-Kang Zhu and Hairong Zhang
Accepted manuscript online: 31 AUG 2016 05:25AM EST | DOI: 10.1111/pce.12826
By using a mapping approach, we cloned AtGCN1, which encodes a homologue of yeast GCN1. Our results showed that AtGCN1 directly interacts with GCN2, forming a complex that is essential for the phosphorylation of the alpha subunit of translation initiation factor eIF2 under a variety of stresses. The atgcn1 mutants were defective in the phosphorylation of eIF2α and were hypersensitive to amino acid starvation and cold stress. Ribosomal profiles showed that the translational state of mRNA was higher in the atgcn1 mutants than in the wild type under cold stress. These results indicate that eIF2α phosphorylation mediated by AtGCN1 inhibits the initiation of protein translation, which contributes to plant tolerance to cold stress.