Nuclear Matrix Protein 4 Is a Novel Regulator of Ribosome Biogenesis and Controls the Unfolded Protein Response via Repression of Gadd34 Expression.

ABSTRACT: The unfolded protein response (UPR) maintains protein homeostasis by governing the processing capacity of the endoplasmic reticulum (ER) to manage ER client loads; however, key regulators within the UPR remain to be identified. Activation of the UPR sensor PERK (EIFAK3/PEK) results in the phosphorylation of the α subunit of eIF2 (eIF2α-P), which represses translation initiation and reduces influx of newly synthesized proteins into the overloaded ER. As part of this adaptive response, eIF2α-P also induces a feedback mechanism through enhanced transcriptional and translational expression of Gadd34 (Ppp1r15A),which targets type 1 protein phosphatase for dephosphorylation of eIF2α-P to restore protein synthesis. Here we describe a novel mechanism by which Gadd34 expression is regulated through

SUBMITTER: Young SK 

PROVIDER: S-EPMC4919460 | biostudies-literature | 2016 Jun

REPOSITORIES: biostudies-literature