Related Experiment Video
Updated: Jul 4, 2026
10:31
Enhanced Crosslinking Immunoprecipitation (eCLIP) Method for Efficient Identification of Protein-bound RNA in Mouse Testis
Published on: May 10, 2019
Capped small RNAs and MOV10 in human hepatitis delta virus replication
Dirk Haussecker1, Dan Cao, Yong Huang
1Department of Pediatrics, Stanford University, 300 Pasteur Dr., Stanford, California 94305, USA.
Nature Structural & Molecular Biology
|June 17, 2008
Summary
Researchers discovered small RNAs and MOV10 protein critical for hepatitis delta virus (HDV) RNA replication. This suggests a conserved RNA-directed transcription mechanism in eukaryotes.
Area of Science:
- Virology
- Molecular Biology
- RNA Biology
Background:
- The replication mechanism of human hepatitis delta virus (HDV) through RNA-directed transcription remains incompletely understood.
- Investigating the evolutionary origins of HDV replication is crucial for understanding viral pathogenesis.
Purpose of the Study:
- To elucidate the molecular mechanisms underlying HDV RNA replication.
- To identify key host factors and RNA elements involved in HDV RNA-directed transcription.
Main Methods:
- Identification and characterization of small RNAs associated with HDV replication.
- Protein-RNA interaction studies using HDAg-interaction screens.
- Functional analysis of MOV10 in HDV replication via knockdown experiments.
Main Results:
- Two species of 5'-capped small RNAs (18-25 nucleotides) were identified, one with antigenomic polarity interacting with HDAg and RNA polymerase II (Pol II).
- Hepatitis delta antigen (HDAg) was found to interact with MOV10, a human homolog of RNA regulatory factors.
- MOV10 knockdown inhibited HDV replication, indicating its essential role in RNA-directed transcription, not HDAg mRNA translation.
Conclusions:
- RNA hairpins are critical for initiating HDV RNA-directed transcription.
- The discovery of capped small RNAs and MOV10 involvement suggests a conserved RNA-directed transcription mechanism shared with lower eukaryotes.
Related Concept Videos
01:29Viruses with RNA Genomes
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...
01:25Inhibitors Of Virion Release
Viral replication and dissemination rely on efficient mechanisms for host cell entry, genome replication, assembly, and release. Influenza viruses, such as types A and B, are negative-sense single-stranded RNA viruses with a segmented genome, that depend on two critical surface glycoproteins to carry out these processes: hemagglutinin (HA) and neuraminidase (NA). HA initiates infection by binding to sialic acid residues on the surface of host epithelial cells, facilitating receptor-mediated...
01:25Hepatitis
Hepatitis is an inflammatory condition of the liver most commonly caused by hepatotropic viruses (A–E), though non-infectious causes such as alcohol and drugs also exist.Hepatitis AHepatitis A virus (HAV) is a non-enveloped RNA virus of the Picornaviridae family. It is primarily transmitted via the fecal-oral route, typically through ingestion of contaminated food or water. After ingestion, HAV enters the bloodstream through the oropharynx or intestinal epithelium and reaches the liver. The...
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...
01:30Inhibitors of Viral Protein Synthesis
Protein synthesis is indispensable for viral replication, as viruses lack the cellular machinery required for this process and must hijack the host's translational apparatus. In response, host cells deploy a critical innate immune defense involving interferons, specialized cytokines that play a central role in inhibiting viral propagation.Upon viral detection, infected cells release interferons that bind to receptors on adjacent uninfected cells, activating the JAK-STAT signaling pathway and...
02:33Retroviruses
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’...