| First Author | Hughes DT | Year | 2020 |
| Journal | Sci Signal | Volume | 13 |
| Issue | 644 | PubMed ID | 32788341 |
| Mgi Jnum | J:311705 | Mgi Id | MGI:6751921 |
| Doi | 10.1126/scisignal.abb4749 | Citation | Hughes DT, et al. (2020) Targeting the kinase insert loop of PERK selectively modulates PERK signaling without systemic toxicity in mice. Sci Signal 13(644) |
| abstractText | Chronic activation of the unfolded protein response (UPR), notably the branch comprising the kinase PERK and the translation initiation factor eIF2alpha, is a pathological feature of many neurodegenerative diseases caused by protein misfolding. Partial reduction of UPR signaling at the level of phosphorylated eIF2alpha is neuroprotective and avoids the pancreatic toxicity caused by full inhibition of PERK kinase activity. However, other stress pathways besides the UPR converge on phosphorylated eIF2alpha in the integrated stress response (ISR), which is critical to normal cellular function. We explored whether partial inhibition of PERK signaling may be a better therapeutic option. PERK-mediated phosphorylation of eIF2alpha requires its binding to the insert loop within PERK's kinase domain, which is, itself, phosphorylated at multiple sites. We found that, as expected, Akt mediates the phosphorylation of Thr(799) in PERK. This phosphorylation event reduced eIF2alpha binding to PERK and selectively attenuated downstream signaling independently of PERK activity and the broader ISR. Induction of Thr(799) phosphorylation with a small-molecule activator of Akt similarly reduced PERK signaling and increased both neuronal and animal survival without measurable pancreatic toxicity in a mouse model of prion disease. Thus, promoting PERK phosphorylation at Thr(799) to partially down-regulate PERK-eIF2alpha signaling while avoiding widespread ISR inhibition may be a safe therapeutic approach in neurodegenerative disease. |
