Related Experiment Video
Updated: Jun 7, 2025
08:26
Purification of Viral DNA for the Identification of Associated Viral and Cellular Proteins
Published on: August 31, 2017
13.6K
Functional 20S Proteasomes in Retroviruses: Evidence in Favor
Vladimir Morozov1, Alexey Morozov2, Vadim L Karpov2
1Department of Infectious Diseases, Robert Koch Institute, 13353 Berlin, Germany.
International Journal of Molecular Sciences
|November 9, 2024
Summary
Functional proteasomes were found associated with various retroviruses, including HIV-1. This study shows proteasome subunits and activity within viruses, suggesting their insertion during viral assembly.
Area of Science:
- Cellular Biology
- Virology
Background:
- Proteasomes are essential cellular complexes for protein degradation.
- Viral assembly can incorporate host cellular proteins.
Purpose of the Study:
- To investigate the presence and function of proteasomes within retroviruses.
- To determine if proteasomes are incorporated into viral particles during assembly.
Main Methods:
- Detection of proteasome subunits in retroviral particles.
- Assaying proteasome activity using fluorescent peptides and probes.
- Analysis of various retroviral types, including lentiviruses and HIV-1.
Main Results:
- Functional 20S proteasomes were associated with gamma-, beta-retroviruses, and lentiviruses.
- Cleaved proteasome subunits (β1, β2, β5) were identified in tested viruses.
- Proteasome activity was confirmed in endogenous, exogenous retroviruses, and recombinant HIV-1.
Conclusions:
- Data supports the insertion of functional proteasomes into retroviruses during their assembly.
- The role of incorporated proteasomes in retroviral biology warrants further investigation.
Related Concept Videos
02:33Retroviruses
12.2K
Retroviruses and retrotransposons both insert copies of their genetic elements into the genome of the host cell. Thus, the viral genes are passed on when the host genome is replicated or translated. A typical retroviral DNA sequence contains 3-4 genes that encode the different proteins required for its structural assembly and function as a molecular parasite. This DNA is transcribed into a single mRNA, which is very similar in structure to conventional mRNAs, i.e., it is capped at the 5’...
12.2K
01:10Retrovirus Life Cycles
45.7K
Retroviruses have a single-stranded RNA genome that undergoes a special form of replication. Once the retrovirus has entered the host cell, an enzyme called reverse transcriptase synthesizes double-stranded DNA from the retroviral RNA genome. This DNA copy of the genome is then integrated into the host’s genome inside the nucleus via an enzyme called integrase. Consequently, the retroviral genome is transcribed into RNA whenever the host’s genome is transcribed, allowing the...
45.7K
01:51Mechanisms of Retrovirus-induced Cancers
5.0K
Retroviruses are RNA viruses that have been shown to cause cancers in diverse species, including chickens, mice, cats, and monkeys. The RNA genomes of these viruses are first reverse-transcribed into single and then double-stranded DNA (dsDNA) copies. This dsDNA called proviral DNA then integrates into the host genome. Subsequently, the host cell transcribes the proviral DNA in concert with the chromosomal DNA. This leads to the production of viral RNA and proteins that assemble at the host...
5.0K
01:17The Proteasome Structure
704
The ubiquitin-proteasome pathway is a well-known mechanism utilized by eukaryotic cells to remove cytoplasmic proteins that are misfolded, damaged, or no longer needed. In this pathway, the protein that needs to be eliminated undergoes a process called ubiquitination, where a chain of ubiquitin molecules is attached to the 48th lysine residue of the target protein. This ubiquitin modification helps the proteasome distinguish between a target protein and a healthy protein.
The proteasome is an...
The proteasome is an...
704
02:18The Proteasome
8.5K
Eukaryotic cells can degrade proteins through several pathways. One of the most important amongst these is the ubiquitin-proteasome pathway. It helps the cell eliminate the misfolded, damaged, or unwarranted cytoplasmic proteins in a highly specific manner.
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. A series of enzymes carry out the ubiquitination of the target proteins - E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. A series of enzymes carry out the ubiquitination of the target proteins - E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...
8.5K
03:18Non-LTR Retrotransposons
11.4K
As the name suggests, non-LTR retrotransposons lack the long terminal repeats characteristic of the LTR retrotransposons. Additionally, both LTR and non-LTR retrotransposons use distinct mechanisms of mobilization. Non-LTR retrotransposons are further divided into two classes - Long interspersed nuclear elements (LINEs) and short interspersed nuclear elements (SINEs), both of which occur abundantly in most mammals, including humans. Some of the active non-LTR retrotransposons in humans are L1...
11.4K