Ca2+ imbalance caused by ERdj5 deletion affects mitochondrial fragmentation

Abstract The endoplasmic reticulum (ER) is the organelle responsible for the folding of secretory/membrane proteins and acts as a dynamic calcium ion (Ca2+) store involved in various cellular signalling pathways. Previously, we reported that the ER-resident disulfide reductase ERdj5 is involved in t...

Full description

Saved in:
Bibliographic Details
Main Authors: Riyuji Yamashita, Shohei Fujii, Ryo Ushioda, Kazuhiro Nagata
Format: article
Language:EN
Published: Nature Portfolio 2021
Subjects:
R
Q
Online Access:https://doaj.org/article/6657b0bd952e4c00b2a5f5b45c8104c7
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Abstract The endoplasmic reticulum (ER) is the organelle responsible for the folding of secretory/membrane proteins and acts as a dynamic calcium ion (Ca2+) store involved in various cellular signalling pathways. Previously, we reported that the ER-resident disulfide reductase ERdj5 is involved in the ER-associated degradation (ERAD) of misfolded proteins in the ER and the activation of SERCA2b, a Ca2+ pump on the ER membrane. These results highlighted the importance of the regulation of redox activity in both Ca2+ and protein homeostasis in the ER. Here, we show that the deletion of ERdj5 causes an imbalance in intracellular Ca2+ homeostasis, the activation of Drp1, a cytosolic GTPase involved in mitochondrial fission, and finally the aberrant fragmentation of mitochondria, which affects cell viability as well as phenotype with features of cellular senescence. Thus, ERdj5-mediated regulation of intracellular Ca2+ is essential for the maintenance of mitochondrial homeostasis involved in cellular senescence.