scholarly journals Degradation of Mutant Protein Aggregates within the Endoplasmic Reticulum of Vasopressin Neurons

iScience ◽  
2020 ◽  
Vol 23 (10) ◽  
pp. 101648
Author(s):  
Takashi Miyata ◽  
Daisuke Hagiwara ◽  
Yuichi Hodai ◽  
Tsutomu Miwata ◽  
Yohei Kawaguchi ◽  
...  
2015 ◽  
Vol 21 (3) ◽  
pp. 173-180
Author(s):  
Hiroshi ARIMA ◽  
Yoshinori AZUMA ◽  
Yoshiaki MORISHITA ◽  
Masayuki HAYASHI ◽  
Daisuke HAGIWARA

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Francisco J Piña ◽  
Maho Niwa

Stress induced by cytoplasmic protein aggregates can have deleterious consequences for the cell, contributing to neurodegeneration and other diseases. Protein aggregates are also formed within the endoplasmic reticulum (ER), although the fate of ER protein aggregates, specifically during cell division, is not well understood. By simultaneous visualization of both the ER itself and ER protein aggregates, we found that ER protein aggregates that induce ER stress are retained in the mother cell by activation of the ER Stress Surveillance (ERSU) pathway, which prevents inheritance of stressed ER. In contrast, under conditions of normal ER inheritance, ER protein aggregates can enter the daughter cell. Thus, whereas cytoplasmic protein aggregates are retained in the mother cell to protect the functional capacity of daughter cells, the fate of ER protein aggregates is determined by whether or not they activate the ERSU pathway to impede transmission of the cortical ER during the cell cycle.


2015 ◽  
Vol 112 (5) ◽  
pp. 1398-1403 ◽  
Author(s):  
Chengcheng Huang ◽  
Yoichiro Harada ◽  
Akira Hosomi ◽  
Yuki Masahara-Negishi ◽  
Junichi Seino ◽  
...  

The cytoplasmic peptide:N-glycanase (PNGase; Ngly1 in mice) is a deglycosylating enzyme involved in the endoplasmic reticulum (ER)-associated degradation (ERAD) process. The precise role of Ngly1 in the ERAD process, however, remains unclear in mammals. The findings reported herein, using mouse embryonic fibroblast (MEF) cells, that the ablation of Ngly1 causes dysregulation of the ERAD process. Interestingly, not only delayed degradation but also the deglycosylation of a misfolded glycoprotein was observed in Ngly1−/− MEF cells. The unconventional deglycosylation reaction was found to be catalyzed by the cytosolic endo-β-N-acetylglucosaminidase (ENGase), generating aggregation-prone N-GlcNAc proteins. The ERAD dysregulation in cells lacking Ngly1 was restored by the additional knockout of ENGase gene. Thus, our study underscores the functional importance of Ngly1 in the ERAD process and provides a potential mechanism underlying the phenotypic consequences of a newly emerging genetic disorder caused by mutation of the human NGLY1 gene.


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