scholarly journals Rice stripe virus activates the bZIP17/28 branch of the unfolded protein response signalling pathway to promote viral infection

2021 ◽  
Author(s):  
Chenyang Li ◽  
Tianze Zhang ◽  
Yu Liu ◽  
Zongdi Li ◽  
Yaqin Wang ◽  
...  
Keyword(s):  
Viral Infection ◽  
Unfolded Protein Response ◽  
Rice Stripe Virus ◽  
Signalling Pathway ◽  
Unfolded Protein ◽  
The Unfolded Protein Response ◽  
Protein Response

scholarly journals Human Cytomegalovirus Infection Activates and Regulates the Unfolded Protein Response

2005 ◽  
Vol 79 (11) ◽  
pp. 6890-6899 ◽  
Author(s):  
Jennifer A. Isler ◽  
Alison H. Skalet ◽  
James C. Alwine
Keyword(s):  
Endoplasmic Reticulum ◽  
Transcription Factor ◽  
Endoplasmic Reticulum Stress ◽  
Viral Infection ◽  
Unfolded Protein Response ◽  
Human Cytomegalovirus ◽  
Hcmv Infection ◽  
Unfolded Protein ◽  
The Unfolded Protein Response ◽  
Protein Response

ABSTRACT Viral infection causes stress to the endoplasmic reticulum. The response to endoplasmic reticulum stress, known as the unfolded protein response (UPR), is designed to eliminate misfolded proteins and allow the cell to recover by attenuating translation and upregulating the expression of chaperones, degradation factors, and factors that regulate the cell's metabolic and redox environment. Some consequences of the UPR (e.g., expression of chaperones and regulation of the metabolism and redox environment) may be advantageous to the viral infection; however, translational attenuation would not. Thus, viruses may induce mechanisms which modulate the UPR, maintaining beneficial aspects and suppressing deleterious aspects. We demonstrate that human cytomegalovirus (HCMV) infection induces the UPR but specifically regulates the three branches of UPR signaling, PKR-like ER kinase (PERK), activating transcription factor 6 (ATF6), and inositol-requiring enzyme 1 (IRE-1), to favor viral replication. HCMV infection activated the eIF2α kinase PERK; however, the amount of phosphorylated eIF2α was limited and translation attenuation did not occur. Interestingly, translation of select mRNAs, which is dependent on eIF2α phosphorylation, did occur, including the transcription factor ATF4, which activates genes which may benefit the infection. The endoplasmic reticulum stress-induced activation of the transcription factor ATF6 was suppressed in HCMV-infected cells; however, specific chaperone genes, normally activated by ATF6, were activated by a virus-induced, ATF6-independent mechanism. Lastly, HCMV infection activated the IRE-1 pathway, as indicated by splicing of Xbp-1 mRNA. However, transcriptional activation of the XBP-1 target gene EDEM (ER degradation-enhancing α-mannosidase-like protein, a protein degradation factor) was inhibited. These results suggest that, although HCMV infection induces the unfolded protein response, it modifies the outcome to benefit viral replication.

scholarly journals Immune regulation of the unfolded protein response at the mucosal barrier in viral infection

2018 ◽  
Vol 7 (4) ◽  
pp. e1014 ◽  
Author(s):  
Ran Wang ◽  
Md. Moniruzzaman ◽  
Eric Shuffle ◽  
Rohan Lourie ◽  
Sumaira Z Hasnain
Keyword(s):  
Viral Infection ◽  
Unfolded Protein Response ◽  
Immune Regulation ◽  
Mucosal Barrier ◽  
Unfolded Protein ◽  
The Unfolded Protein Response ◽  
Protein Response

Repression of N-glycosylation triggers the unfolded protein response (UPR) and overexpression of cell wall protein and chitin in Aspergillus fumigatus

Microbiology ◽  
2011 ◽  
Vol 157 (7) ◽  
pp. 1968-1979 ◽  
Author(s):  
Kai Li ◽  
Haomiao Ouyang ◽  
Yang Lü ◽  
Jingnan Liang ◽  
Iain B. H. Wilson ◽  
...  
Keyword(s):  
Cell Wall ◽  
Aspergillus Fumigatus ◽  
Unfolded Protein Response ◽  
Cell Wall Protein ◽  
Signalling Pathway ◽  
Cell Wall Biosynthesis ◽  
Unfolded Protein ◽  
Cell Wall Biogenesis ◽  
The Unfolded Protein Response ◽  
Protein Response

Aspergillus fumigatus is the most common airborne fungal pathogen, causing fatal invasive aspergillosis in immunocompromised patients. The crude mortality is 60–90 % and remains around 29–42 % even with treatment. The main reason for patient death is the low efficiency of the drug therapies. As protein N-glycosylation is involved in cell wall biogenesis in A. fumigatus, a deeper understanding of its role in cell wall biogenesis will help to develop new drug targets. The Afstt3 gene encodes the essential catalytic subunit of oligosaccharyltransferase, an enzyme complex responsible for the transfer of the N-glycan to nascent polypeptides. To evaluate the role of N-glycosylation in cell wall biosynthesis, we constructed the conditional mutant strain CPR-stt3 by replacing the endogenous promoter of Afstt3 with the nitrogen-dependent niiA promoter. Repression of the Afstt3 gene in the CPR-stt3 strain led to a severe retardation of growth and a slight defect in cell wall integrity (CWI). One of the most interesting findings was that upregulation of the cell wall-related genes was not accompanied by an activation of the MpkA kinase, which has been shown to be a central element in the CWI signalling pathway in both Saccharomyces cerevisiae and A. fumigatus. Considering that the unfolded protein response (UPR) was found to be activated, which might upregulate the expression of cell wall protein and chitin, our data suggest that the UPR, instead of the MpkA-dependent CWI signalling pathway, is the major compensatory mechanism induced by repression but not abolition of N-glycosylation in A. fumigatus. Our finding is a key to understanding the complex compensatory mechanisms of cell wall biosynthesis and may provide a new strategy for drug development.

Presenilin-1 mutations downregulate the signalling pathway of the unfolded-protein response

10.1038/70265 ◽  
1999 ◽  
Vol 1 (8) ◽  
pp. 479-485 ◽  
Author(s):  
Taiichi Katayama ◽  
Kazunori Imaizumi ◽  
Naoya Sato ◽  
Ko Miyoshi ◽  
Takashi Kudo ◽  
...  
Keyword(s):  
Unfolded Protein Response ◽  
Signalling Pathway ◽  
Presenilin 1 ◽  
Unfolded Protein ◽  
The Unfolded Protein Response ◽  
Protein Response

Oestrogen-driven changes in the bovine uterus are associated with activation of the unfolded protein response

2014 ◽  
Author(s):  
Mohammed A Alfattah ◽  
Paul Anthony McGettigan ◽  
John Arthur Browne ◽  
Khalid M Alkhodair ◽  
Katarzyna Pluta ◽  
...  
Keyword(s):  
Unfolded Protein Response ◽  
Unfolded Protein ◽  
The Unfolded Protein Response ◽  
Protein Response
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