The Structure of the PERK Kinase Domain Suggests the Mechanism for Its Activation
Overview
Authors
Affiliations
The endoplasmic reticulum (ER) unfolded protein response (UPR) is comprised of several intracellular signaling pathways that alleviate ER stress. The ER-localized transmembrane kinase PERK is one of three major ER stress transducers. Oligomerization of PERK's N-terminal ER luminal domain by ER stress promotes PERK trans-autophosphorylation of the C-terminal cytoplasmic kinase domain at multiple residues including Thr980 on the kinase activation loop. Activated PERK phosphorylates Ser51 of the α-subunit of translation initiation factor 2 (eIF2α), which inhibits initiation of protein synthesis and reduces the load of unfolded proteins entering the ER. The crystal structure of PERK's kinase domain has been determined to 2.8 Å resolution. The structure resembles the back-to-back dimer observed in the related eIF2α kinase PKR. Phosphorylation of Thr980 stabilizes both the activation loop and helix αG in the C-terminal lobe, preparing the latter for eIF2α binding. The structure suggests conservation in the mode of activation of eIF2α kinases and is consistent with a `line-up' model for PERK activation triggered by oligomerization of its luminal domain.
Suppression of stress granule formation is a vulnerability imposed by mutant p53.
Thoenen E, Ranjan A, Parrales A, Nishikawa S, Dixon D, Oka S Nat Commun. 2025; 16(1):2365.
PMID: 40064891 PMC: 11894096. DOI: 10.1038/s41467-025-57539-6.
Solorio-Kirpichyan K, Fan X, Golovenko D, Korostelev A, Yan N, Korennykh A PNAS Nexus. 2024; 3(12):pgae528.
PMID: 39618511 PMC: 11606652. DOI: 10.1093/pnasnexus/pgae528.
Navigating the landscape of the unfolded protein response in CD8 T cells.
Nair 2nd K, Liu B Front Immunol. 2024; 15:1427859.
PMID: 39026685 PMC: 11254671. DOI: 10.3389/fimmu.2024.1427859.
Yuvaraj S, Vasudevan V, Puhari S, Sasikumar S, Ramprasath T, Selvi M Mol Biol Rep. 2024; 51(1):678.
PMID: 38796673 DOI: 10.1007/s11033-024-09612-4.
Regulation of cardiac fibroblast cell death by unfolded protein response signaling.
Rowland M, Moore P, Correll R Front Physiol. 2024; 14:1304669.
PMID: 38283278 PMC: 10811265. DOI: 10.3389/fphys.2023.1304669.