... Under con-ditions of low glucose concentration, translation of proinsulin in pancreatic b-cells is repressed by activa-tion of PERK, and the UPR controls the terminal dif-ferentiation of B-cells ... theexpression of ER-localized molecular chaperones[80,81]. Transcription from another cis-acting regula-tory element, XBP1-BS, is entirely controlled byXBP1, and induces expression of components of ... specific serine residue of transla-tion initiation factor-2a (eIF2a), resulting in generalinhibition of translation [16,29]. Phosphorylation of eIF2a also stimulates translation of ATF4 [30], abZIP-like...