Related Experiment Video
Updated: May 30, 2026
09:35
Using Click Chemistry to Measure the Effect of Viral Infection on Host-Cell RNA Synthesis
Published on: August 9, 2013
Rotavirus infection activates the UPR but modulates its activity.
Jose Luis Zambrano1, Khalil Ettayebi, Walid S Maaty
1Immunology and Infectious Diseases, Montana State University, Bozeman, MT 59718, USA.
Virology Journal
|July 22, 2011
Summary
Rotavirus infection activates the unfolded protein response (UPR) but sequesters UPR proteins in viroplasms. This suggests viroplasms regulate cellular defense signaling pathways during rotavirus infection.
Area of Science:
- Virology
- Cellular Biology
- Immunology
Background:
- Rotaviruses are known to interfere with the host's innate antiviral defense mechanisms, particularly the interferon (IFN) response.
- Understanding host-pathogen interactions at the proteomic level is crucial for identifying new therapeutic targets.
Purpose of the Study:
- To identify proteomic changes in host cells upon rotavirus infection, focusing on the interplay with the IFN response.
- To discover proteins modulated by rotavirus infection that are independent of the IFN induction and signaling pathways.
Main Methods:
- Differential gel electrophoresis (2D-DIGE) and image analysis were employed to detect changes in protein expression levels.
- Immunofluorescence microscopy was utilized to determine the subcellular localization of key proteins, including those involved in the unfolded protein response (UPR).
Main Results:
- Rotavirus infection led to alterations in proteins associated with cellular stress, notably endoplasmic reticulum (ER) chaperones GRP78 and GRP94.
- Proteins involved in the ER-initiated UPR, including PERK, CHOP, and GADD34, were found to co-localize with viroplasms in infected cells.
Conclusions:
- Rotavirus infection activates the UPR, but the virus appears to modulate its effects by sequestering UPR-related proteins within viroplasms.
- Viroplasms may play a significant role in regulating cellular defense signaling pathways, either directly or indirectly, during rotavirus infection.
Related Concept Videos
01:31Regulation of the Unfolded Protein Response
Inositol-requiring kinase one or IRE1 is the most conserved eukaryotic unfolded protein response (UPR) receptor. It is a type I transmembrane protein kinase receptor with a distinctive site-specific RNase activity. As the binding mechanics of the misfolded proteins with the N-terminal domain of IRE-1 are unclear, three binding models — direct, indirect, and allosteric -- are proposed for receptor activation. Nevertheless, it is known that once a misfolded protein associates with IRE1, it...
01:37The Unfolded Protein Response
The ER is the hub of protein synthesis in a cell. It has robust systems to quality control protein folding and also for degradation of terminally misfolded proteins. Under normal conditions, a small proportion of misfolded proteins that cannot be salvaged need to be transported to the cytoplasm by the ER-associated degradation or ERAD pathways. However, if the ERAD cannot handle the misfolded proteins, the cell activates the unfolded protein response or UPR to adjust the protein folding...
01:29Respiratory Syncytial Virus Disease
Human respiratory syncytial virus (RSV) is a widespread pathogen that primarily targets infants and young children but also poses a serious health risk to elderly and immunocompromised individuals. Belonging to the Pneumoviridae family, RSV is a negative-sense, single-stranded RNA virus within the Pneumovirus genus. Its global health burden is significant, with millions of cases annually resulting in hospitalizations and mortality, particularly in resource-limited settings. Although most...
01:09GPCRs Regulate Adenylyl Cylase Activity
Some GPCRs transmit signals through adenylyl cyclase (AC), a transmembrane enzyme. AC helps synthesize second messenger cyclic adenosine monophosphate (cAMP). AC catalyzes cyclization reaction and converts ATP to cAMP by releasing a pyrophosphate. The pyrophosphate is further hydrolyzed to phosphate by the enzyme pyrophosphatase, which drives cAMP synthesis to completion. However, cAMP is rapidly degraded to 5′ AMP by the enzymes phosphodiesterase (PDE), preventing overstimulation of cells.
Two...
Two...
01:03Rous Sarcoma Virus (RSV) and Cancer
Rous Sarcoma virus or RSV was discovered by F. Peyton Rous in the year 1911 as a filterable transmissible agent that could cause tumors in chickens. He won a Nobel Prize for this discovery in 1966. His experiments clearly demonstrated that some cancers could be caused by infectious agents and led to the discovery of many more cancer-causing viruses in animals as well as humans.
RSV is a retrovirus that contains two copies of a plus-strand RNA genome. Its genome consists of four main open...
RSV is a retrovirus that contains two copies of a plus-strand RNA genome. Its genome consists of four main open...
02:28Leaky Scanning
During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA. Marilyn Kozak discovered that the sequence RCCAUGG (where R stands for...