Targeted redox inhibition of protein phosphatase 1 by Nox4 regulates eIF2α-mediated stress signaling.
EMBO J
; 35(3): 319-34, 2016 Feb 01.
Article
en En
| MEDLINE
| ID: mdl-26742780
ABSTRACT
Phosphorylation of translation initiation factor 2α (eIF2α) attenuates global protein synthesis but enhances translation of activating transcription factor 4 (ATF4) and is a crucial evolutionarily conserved adaptive pathway during cellular stresses. The serine-threonine protein phosphatase 1 (PP1) deactivates this pathway whereas prolonging eIF2α phosphorylation enhances cell survival. Here, we show that the reactive oxygen species-generating NADPH oxidase-4 (Nox4) is induced downstream of ATF4, binds to a PP1-targeting subunit GADD34 at the endoplasmic reticulum, and inhibits PP1 activity to increase eIF2α phosphorylation and ATF4 levels. Other PP1 targets distant from the endoplasmic reticulum are unaffected, indicating a spatially confined inhibition of the phosphatase. PP1 inhibition involves metal center oxidation rather than the thiol oxidation that underlies redox inhibition of protein tyrosine phosphatases. We show that this Nox4-regulated pathway robustly enhances cell survival and has a physiologic role in heart ischemia-reperfusion and acute kidney injury. This work uncovers a novel redox signaling pathway, involving Nox4-GADD34 interaction and a targeted oxidative inactivation of the PP1 metal center, that sustains eIF2α phosphorylation to protect tissues under stress.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Transducción de Señal
/
Factor 2 Eucariótico de Iniciación
/
Receptores de Neuropéptido Y
/
NADPH Oxidasas
/
Proteína Fosfatasa 1
Límite:
Animals
/
Humans
Idioma:
En
Revista:
EMBO J
Año:
2016
Tipo del documento:
Article
País de afiliación:
Reino Unido