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Nature Reviews. Microbiology Aug 2015Major advances have occurred in recent years in our understanding of HIV-1 assembly, release and maturation, as work in this field has been propelled forwards by... (Review)
Review
Major advances have occurred in recent years in our understanding of HIV-1 assembly, release and maturation, as work in this field has been propelled forwards by developments in imaging technology, structural biology, and cell and molecular biology. This increase in basic knowledge is being applied to the development of novel inhibitors designed to target various aspects of virus assembly and maturation. This Review highlights recent progress in elucidating the late stages of the HIV-1 replication cycle and the related interplay between virology, cell and molecular biology, and drug discovery.
Topics: Gene Expression Regulation, Viral; HIV-1; Humans; Viral Proteins; Virus Assembly; Virus Release; Virus Replication
PubMed: 26119571
DOI: 10.1038/nrmicro3490 -
Autophagy Jul 2022Severe fever with thrombocytopenia syndrome virus (SFTSV) is an emerging negatively stranded enveloped RNA bunyavirus that causes SFTS with a high case fatality rate of...
Severe fever with thrombocytopenia syndrome virus (SFTSV) is an emerging negatively stranded enveloped RNA bunyavirus that causes SFTS with a high case fatality rate of up to 30%. Macroautophagy/autophagy is an evolutionarily conserved process involved in the maintenance of host homeostasis, which exhibits anti-viral or pro-viral responses in reaction to different viral challenges. However, the interaction between the bunyavirus SFTSV and the autophagic process is still largely unclear. By establishing various autophagy-deficient cell lines, we found that SFTSV triggered RB1CC1/FIP200-BECN1-ATG5-dependent classical autophagy flux. SFTSV nucleoprotein induced BECN1-dependent autophagy by disrupting the BECN1-BCL2 association. Importantly, SFTSV utilized autophagy for the viral life cycle, which not only assembled in autophagosomes derived from the ERGIC and Golgi complex, but also utilized autophagic vesicles for exocytosis. Taken together, our results suggest a novel virus-autophagy interaction model in which bunyavirus SFTSV induces classical autophagy flux for viral assembly and egress processes, suggesting that autophagy inhibition may be a novel therapy for treating or releasing SFTS.
Topics: Autophagy; Humans; Orthobunyavirus; Phlebovirus; Severe Fever with Thrombocytopenia Syndrome; Virus Assembly
PubMed: 34747299
DOI: 10.1080/15548627.2021.1994296 -
The Journal of General Virology Aug 2016Clinical isolates of influenza virus produce pleomorphic virus particles, including extremely long filamentous virions. In contrast, strains of influenza that have... (Review)
Review
Clinical isolates of influenza virus produce pleomorphic virus particles, including extremely long filamentous virions. In contrast, strains of influenza that have adapted to laboratory growth typically produce only spherical virions. As a result, the filamentous phenotype has been overlooked in most influenza virus research. Recent advances in imaging and improved animal models have highlighted the distinct structure and functional relevance of filamentous virions. In this review we summarize what is currently known about these strikingly elongated virus particles and discuss their possible roles in clinical infections.
Topics: Animals; Humans; Orthomyxoviridae; Virus Assembly
PubMed: 27365089
DOI: 10.1099/jgv.0.000535 -
Viruses May 2022Two non-covalently linked copies of the retrovirus genome are specifically recruited to the site of virus particle assembly and packaged into released particles.... (Review)
Review
Two non-covalently linked copies of the retrovirus genome are specifically recruited to the site of virus particle assembly and packaged into released particles. Retroviral RNA packaging requires RNA export of the unspliced genomic RNA from the nucleus, translocation of the genome to virus assembly sites, and specific interaction with Gag, the main viral structural protein. While some aspects of the RNA packaging process are understood, many others remain poorly understood. In this review, we provide an update on recent advancements in understanding the mechanism of RNA packaging for retroviruses that cause disease in humans, i.e., HIV-1, HIV-2, and HTLV-1, as well as advances in the understanding of the details of genomic RNA nuclear export, genome translocation to virus assembly sites, and genomic RNA dimerization.
Topics: Genomics; HIV-1; Humans; RNA, Viral; Retroviridae; Virus Assembly
PubMed: 35632835
DOI: 10.3390/v14051094 -
Trends in Microbiology Aug 2019Successful replication of the AIDS retrovirus, HIV, requires that its genomic RNA be packaged in assembling virus particles with high fidelity. However, cellular mRNAs... (Review)
Review
Successful replication of the AIDS retrovirus, HIV, requires that its genomic RNA be packaged in assembling virus particles with high fidelity. However, cellular mRNAs can also be packaged under some conditions. Viral RNA (vRNA) contains a 'packaging signal' (ψ) and is packaged as a dimer, with two vRNA monomers joined by a limited number of base pairs. It has two conformers, only one of which is capable of dimerization and packaging. Recent years have seen important progress on the 3D structure of dimeric ψ. Gag, the protein that assembles into the virus particle, interacts specifically with ψ, but this is obscured under physiological conditions by its high nonspecific affinity for any RNA. New results suggest that vRNA is selected for packaging because ψ nucleates assembly more efficiently than other RNAs.
Topics: HIV-1; Humans; RNA, Viral; Virus Assembly; gag Gene Products, Human Immunodeficiency Virus
PubMed: 31085095
DOI: 10.1016/j.tim.2019.04.003 -
Annual Review of Physical Chemistry Apr 2015Viruses are nanoscale entities containing a nucleic acid genome encased in a protein shell called a capsid and in some cases are surrounded by a lipid bilayer membrane.... (Review)
Review
Viruses are nanoscale entities containing a nucleic acid genome encased in a protein shell called a capsid and in some cases are surrounded by a lipid bilayer membrane. This review summarizes the physics that govern the processes by which capsids assemble within their host cells and in vitro. We describe the thermodynamics and kinetics for the assembly of protein subunits into icosahedral capsid shells and how these are modified in cases in which the capsid assembles around a nucleic acid or on a lipid bilayer. We present experimental and theoretical techniques used to characterize capsid assembly, and we highlight aspects of virus assembly that are likely to receive significant attention in the near future.
Topics: Antiviral Agents; Capsid; DNA, Viral; Drug Discovery; Genome, Viral; Humans; Models, Molecular; RNA, Viral; Thermodynamics; Virus Assembly; Virus Diseases; Virus Physiological Phenomena; Viruses
PubMed: 25532951
DOI: 10.1146/annurev-physchem-040214-121637 -
ELife Dec 2023Nucleotide and force-dependent mechanisms control how the viral genome of lambda bacteriophage is inserted into capsids.
Nucleotide and force-dependent mechanisms control how the viral genome of lambda bacteriophage is inserted into capsids.
Topics: DNA, Viral; Bacteriophage lambda; Capsid; Genome, Viral; Nucleotides; Virus Assembly
PubMed: 38095555
DOI: 10.7554/eLife.94128 -
Trends in Biochemical Sciences May 2021Virion assembly is an important step in the life cycle of all viruses. For viruses of the Flavivirus genus, a group of enveloped positive-sense RNA viruses, the assembly... (Review)
Review
Virion assembly is an important step in the life cycle of all viruses. For viruses of the Flavivirus genus, a group of enveloped positive-sense RNA viruses, the assembly step represents one of the least understood processes in the viral life cycle. While assembly is primarily driven by the viral structural proteins, recent studies suggest that several nonstructural proteins also play key roles in coordinating the assembly and packaging of the viral genome. This review focuses on describing recent advances in our understanding of flavivirus virion assembly, including the intermolecular interactions between the viral structural (capsid) and nonstructural proteins (NS2A and NS2B-NS3), host factors, as well as features of the viral genomic RNA required for efficient flavivirus virion assembly.
Topics: Flavivirus; RNA, Viral; Viral Nonstructural Proteins; Virion; Virus Assembly
PubMed: 33423940
DOI: 10.1016/j.tibs.2020.12.007 -
Cold Spring Harbor Perspectives in... Nov 2015This work reviews specific related aspects of hepatitis delta virus (HDV) reproduction, including virion structure, the RNA genome, the mode of genome replication, the... (Review)
Review
This work reviews specific related aspects of hepatitis delta virus (HDV) reproduction, including virion structure, the RNA genome, the mode of genome replication, the delta antigens, and the assembly of HDV using the envelope proteins of its helper virus, hepatitis B virus (HBV). These topics are considered with perspectives ranging from a history of discovery through to still-unsolved problems. HDV evolution, virus entry, and associated pathogenic potential and treatment of infections are considered in other articles in this collection.
Topics: Hepatitis D; Hepatitis Delta Virus; Humans; Virus Assembly; Virus Replication
PubMed: 26525452
DOI: 10.1101/cshperspect.a021568 -
Viruses Dec 2021Retroviruses have a very complex and tightly controlled life cycle which has been studied intensely for decades. After a virus enters the cell, it reverse-transcribes... (Review)
Review
Retroviruses have a very complex and tightly controlled life cycle which has been studied intensely for decades. After a virus enters the cell, it reverse-transcribes its genome, which is then integrated into the host genome, and subsequently all structural and regulatory proteins are transcribed and translated. The proteins, along with the viral genome, assemble into a new virion, which buds off the host cell and matures into a newly infectious virion. If any one of these steps are faulty, the virus cannot produce infectious viral progeny. Recent advances in structural and molecular techniques have made it possible to better understand this class of viruses, including details about how they regulate and coordinate the different steps of the virus life cycle. In this review we summarize the molecular analysis of the assembly and maturation steps of the life cycle by providing an overview on structural and biochemical studies to understand these processes. We also outline the differences between various retrovirus families with regards to these processes.
Topics: Capsid; Cryoelectron Microscopy; Genome, Viral; HIV-1; Humans; Models, Molecular; Retroviridae; Virion; Virus Assembly
PubMed: 35062258
DOI: 10.3390/v14010054