Signaling pathways engaged in SGs formation. Once cells are exposed to diverse stresses, eIF2α can be phosphorylated by stress-sensing kinases (HRI, GCN2, PKR and PERK). Phosphorylated eIF2α inhibits translation initiation and triggers assembly of SGs. On the other hand, SGs assembly can be induced independently of eIF2α phosphorylation. When the eIF4F (eIF4A-eIF4E-eIF4G) complex is dissociated, translation inhibition occurs, thereby promoting assembly of SGs. Finally, mTORC1 contributes to increase SGs formation. In brief, during mild oxidative stress, mTORC1 can induce assembly of SGs through promoting eIF2α phosphorylation, and mTORC1 can increase persistence of SGs through inhibiting autophagy which regulates SGs clearance.
