scholarly journals Role of Unfolded Protein Response and Endoplasmic Reticulum-Associated Degradation by Repeated Exposure to Inhalation Anesthetics in Caenorhabditis elegans

2021 ◽  
Vol 18 (13) ◽  
pp. 2890-2896
Author(s):  
Saeyeon Kim ◽  
Hyun-Jung Shin ◽  
Sang-Hwan Do ◽  
Hyo-Seok Na
Keyword(s):  
Endoplasmic Reticulum ◽  
Caenorhabditis Elegans ◽  
Unfolded Protein Response ◽  
Repeated Exposure ◽  
Inhalation Anesthetics ◽  
Unfolded Protein ◽  
Endoplasmic Reticulum Associated Degradation ◽  
Protein Response

scholarly journals A Role for the DnaJ Homologue Scj1p in Protein Folding in the Yeast Endoplasmic Reticulum

1998 ◽  
Vol 143 (4) ◽  
pp. 921-933 ◽  
Author(s):  
Susana Silberstein ◽  
Gabriel Schlenstedt ◽  
Pam A. Silver ◽  
Reid Gilmore
Keyword(s):  
Endoplasmic Reticulum ◽  
Unfolded Protein Response ◽  
Physiological Role ◽  
Carboxypeptidase Y ◽  
Reporter Protein ◽  
Unfolded Protein ◽  
A Cell ◽  
The Unfolded Protein Response ◽  
Protein Response

Members of the eukaryotic heat shock protein 70 family (Hsp70s) are regulated by protein cofactors that contain domains homologous to bacterial DnaJ. Of the three DnaJ homologues in the yeast rough endoplasmic reticulum (RER; Scj1p, Sec63p, and Jem1p), Scj1p is most closely related to DnaJ, hence it is a probable cofactor for Kar2p, the major Hsp70 in the yeast RER. However, the physiological role of Scj1p has remained obscure due to the lack of an obvious defect in Kar2p-mediated pathways in scj1 null mutants. Here, we show that the Δscj1 mutant is hypersensitive to tunicamycin or mutations that reduce N-linked glycosylation of proteins. Although maturation of glycosylated carboxypeptidase Y occurs with wild-type kinetics in Δscj1 cells, the transport rate for an unglycosylated mutant carboxypeptidase Y (CPY) is markedly reduced. Loss of Scj1p induces the unfolded protein response pathway, and results in a cell wall defect when combined with an oligosaccharyltransferase mutation. The combined loss of both Scj1p and Jem1p exaggerates the sensitivity to hypoglycosylation stress, leads to further induction of the unfolded protein response pathway, and drastically delays maturation of an unglycosylated reporter protein in the RER. We propose that the major role for Scj1p is to cooperate with Kar2p to mediate maturation of proteins in the RER lumen.

scholarly journals Degradation of a Short-lived Glycoprotein from the Lumen of the Endoplasmic Reticulum: The Role of N-linked Glycans and the Unfolded Protein Response

1999 ◽  
Vol 10 (12) ◽  
pp. 4059-4073 ◽  
Author(s):  
Maddalena de Virgilio ◽  
Claudia Kitzmüller ◽  
Eva Schwaiger ◽  
Michael Klein ◽  
Gert Kreibich ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Unfolded Protein Response ◽  
The Other ◽  
Slow Phase ◽  
Type I ◽  
Unfolded Protein ◽  
Other Hand ◽  
The Unfolded Protein Response ◽  
Protein Response

We are studying endoplasmic reticulum–associated degradation (ERAD) with the use of a truncated variant of the type I ER transmembrane glycoprotein ribophorin I (RI). The mutant protein, RI332, containing only the N-terminal 332 amino acids of the luminal domain of RI, has been shown to interact with calnexin and to be a substrate for the ubiquitin-proteasome pathway. When RI332 was expressed in HeLa cells, it was degraded with biphasic kinetics; an initial, slow phase of ∼45 min was followed by a second phase of threefold accelerated degradation. On the other hand, the kinetics of degradation of a form of RI332 in which the single used N-glycosylation consensus site had been removed (RI332-Thr) was monophasic and rapid, implying a role of the N-linked glycan in the first proteolytic phase. RI332degradation was enhanced when the binding of glycoproteins to calnexin was prevented. Moreover, the truncated glycoprotein interacted with calnexin preferentially during the first proteolytic phase, which strongly suggests that binding of RI332 to the lectin-like protein may result in the slow, initial phase of degradation. Additionally, mannose trimming appears to be required for efficient proteolysis of RI332. After treatment of cells with the inhibitor of N-glycosylation, tunicamycin, destruction of the truncated RI variants was severely inhibited; likewise, in cells preincubated with the calcium ionophore A23187, both RI332 and RI332-Thr were stabilized, despite the presence or absence of the N-linked glycan. On the other hand, both drugs are known to trigger the unfolded protein response (UPR), resulting in the induction of BiP and other ER-resident proteins. Indeed, only in drug-treated cells could an interaction between BiP and RI332 and RI332-Thr be detected. Induction of BiP was also evident after overexpression of murine Ire1, an ER transmembrane kinase known to play a central role in the UPR pathway; at the same time, stabilization of RI332 was observed. Together, these results suggest that binding of the substrate proteins to UPR-induced chaperones affects their half lives.

scholarly journals Unfolded protein response in brain ischemia: A timely update

2016 ◽  
Vol 36 (12) ◽  
pp. 2044-2050 ◽  
Author(s):  
Wei Yang ◽  
Wulf Paschen
Keyword(s):  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Unfolded Protein Response ◽  
Brain Ischemia ◽  
Unfolded Protein ◽  
Vital Functions ◽  
Advance Research ◽  
The Unfolded Protein Response ◽  
Protein Response

Folding and processing newly synthesized proteins are vital functions of the endoplasmic reticulum that are sensitive to a variety of stress conditions. The unfolded protein response is activated to restore endoplasmic reticulum function impaired by stress. While we know that brain ischemia impairs endoplasmic reticulum function, the role of unfolded protein response activation in post-ischemic recovery of neurologic function is only beginning to emerge. Here, we summarize what is known about endoplasmic reticulum stress and unfolded protein response in brain ischemia and discuss recent findings from myocardial ischemia studies that could help to advance research on endoplasmic reticulum stress and unfolded protein response in brain ischemia.

scholarly journals Regulation of the unfolded protein response by microRNAs

2013 ◽  
Vol 18 (4) ◽  
Author(s):  
Sylwia Bartoszewska ◽  
Kinga Kochan ◽  
Piotr Madanecki ◽  
Arkadiusz Piotrowski ◽  
Renata Ochocka ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Unfolded Protein Response ◽  
Potential Role ◽  
Recovery Phase ◽  
Cellular Mechanisms ◽  
Unfolded Protein ◽  
Critical Components ◽  
The Unfolded Protein Response ◽  
Protein Response

AbstractThe unfolded protein response (UPR) is an adaptive response to the stress that is caused by an accumulation of misfolded proteins in the lumen of the endoplasmic reticulum (ER). It is an important component of cellular homeostasis. During ER stress, the UPR increases the protein-folding capacity of the endoplasmic reticulum to relieve the stress. Failure to recover leads to apoptosis. Specific cellular mechanisms are required for the cellular recovery phase after UPR activation. Using bioinformatics tools, we identified a number of microRNAs that are predicted to decrease the mRNA expression levels for a number of critical components of the UPR. In this review, we discuss the potential role of microRNAs as key regulators of this pathway and describe how microRNAs may play an essential role in turning off the UPR after the stress has subsided.

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