Related Experiment Video
Updated: Aug 26, 2025
05:55
Identifying Inhibitors of the HBx-DDB1 Interaction Using a Split Luciferase Assay System
Published on: December 21, 2019
6.8K
Hepatitis B virus polymerase restricts LINE-1 mobility
1Management Department of Biosafety, Laboratory Animal, and Pathogen Bank, National Institute of Infectious Diseases, Tokyo 208-0011, Japan; Division of Retroelement, Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto 860-0811, Japan.
Gene
|October 5, 2022
Summary
Hepatitis B virus (HBV) restricts the movement of Long Interspersed Element-1 (LINE-1) in the human genome. HBV polymerase (Pol) inhibits LINE-1 retrotransposition through its ribonuclease H domain and by interacting with LINE-1 proteins.
Area of Science:
- Genetics
- Molecular Biology
- Virology
Background:
- Long Interspersed Element-1 (LINE-1, L1) constitutes approximately 17% of the human genome.
- The interactions between L1 and hepatitis B virus (HBV) are not well understood.
Purpose of the Study:
- To investigate the mechanisms by which HBV influences L1 retrotransposition.
- To elucidate the role of HBV polymerase (Pol) in regulating L1 mobility.
Main Methods:
- Assessing L1 retrotransposition in the presence of HBV components.
- Investigating the interaction between HBV Pol and L1 ORF1p.
- Analyzing the effect of HBV Pol on L1 5' untranslated region (UTR).
Main Results:
- HBV restricts L1 retrotransposition independently of its reverse transcriptase (RT) activity.
- HBV Pol significantly inhibits L1 retrotransposition, with the ribonuclease H (RNase H) domain being crucial for this effect.
- HBV Pol interacts with and sequesters L1 ORF1p, an RNA-binding protein, from P-bodies.
- HBV Pol represses the L1 5' UTR, further contributing to the inhibition of L1 mobility.
Conclusions:
- HBV restricts L1 retrotransposition at multiple stages.
- HBV Pol possesses a novel function in regulating L1 retrotransposition, involving protein-protein interactions and UTR binding.
Related Concept Videos
01:29Viruses with RNA Genomes
94
RNA viruses are categorized into positive-strand, negative-strand, or double-stranded groups based on their genomic structure and replication mechanisms. This classification dictates how they exploit host cellular machinery for protein synthesis and replication. Some RNA viruses also utilize reverse transcription as part of their life cycle, further diversifying their replication strategies.Positive-Strand RNA VirusesPositive-strand RNA viruses have genomes that function directly as messenger...
94
03:18Non-LTR Retrotransposons
11.7K
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...
11.7K
02:28Leaky Scanning
5.2K
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...
5.2K
03:08LTR Retrotransposons
17.8K
LTR retrotransposons are class I transposable elements with long terminal repeats flanking an internal coding region. These elements are less abundant in mammals compared to other class I transposable elements. About 8 percent of human genomic DNA comprises LTR retrotransposons. Some of the common examples of LTR retrotransposons are Ty elements in yeast and Copia elements in Drosophila.
The internal coding region of LTR retrotransposons and their mechanism of transposition closely resembles a...
The internal coding region of LTR retrotransposons and their mechanism of transposition closely resembles a...
17.8K
02:10Translesion DNA Polymerases
10.1K
Translesion (TLS) polymerases rescue stalled DNA polymerases at sites of damaged bases by replacing the replicative polymerase and installing a nucleotide across the damaged site. Doing so, TLS allows additional time for the cell to repair the damage before resuming regular DNA replication.
TLS polymerases are found in all three domains of life - archaea, bacteria, and eukaryotes. Of the different classes of TLS polymerases, members of the Y family are fitted with specialized structures that...
TLS polymerases are found in all three domains of life - archaea, bacteria, and eukaryotes. Of the different classes of TLS polymerases, members of the Y family are fitted with specialized structures that...
10.1K
02:37Restarting Stalled Replication Forks
5.9K
DNA replication is initiated at sites containing predefined DNA sequences known as origins of replication. DNA is unwound at these sites by the minichromosome maintenance (MCM) helicase and other factors such as Cdc45 and the associated GINS complex.The unwound single strands are protected by replication protein A (RPA) until DNA polymerase starts synthesizing DNA at the 5’ end of the strand in the same direction as the replication fork. To prevent the replication fork from falling apart,...
5.9K