The proteasome biogenesis regulator Rpn4 cooperates with the unfolded protein response to promote ER stress resistance

eLife

Rolf M Schmidt¹  Sebastian Schuck¹  Julia P Schessner²  Georg HH Borner² 

[1] Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance and CellNetworks Cluster of Excellence, Heidelberg, Germany;Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, Germany;

关键词: endoplasmic reticulum stress;    unfolded protein response;    Rpn4 regulon;    proteasome biogenesis;    protein degradation;   

DOI  :  10.7554/eLife.43244

来源: DOAJ

【 摘 要 】

Misfolded proteins in the endoplasmic reticulum (ER) activate the unfolded protein response (UPR), which enhances protein folding to restore homeostasis. Additional pathways respond to ER stress, but how they help counteract protein misfolding is incompletely understood. Here, we develop a titratable system for the induction of ER stress in yeast to enable a genetic screen for factors that augment stress resistance independently of the UPR. We identify the proteasome biogenesis regulator Rpn4 and show that it cooperates with the UPR. Rpn4 abundance increases during ER stress, first by a post-transcriptional, then by a transcriptional mechanism. Induction of RPN4 transcription is triggered by cytosolic mislocalization of secretory proteins, is mediated by multiple signaling pathways and accelerates clearance of misfolded proteins from the cytosol. Thus, Rpn4 and the UPR are complementary elements of a modular cross-compartment response to ER stress.

【 授权许可】

Unknown