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The Journal of General Virology Dec 2021Viruses in the family are found in a wide variety of vertebrate hosts. Enveloped virions are 80-100 nm in diameter with an inner core containing the viral genome and...
Viruses in the family are found in a wide variety of vertebrate hosts. Enveloped virions are 80-100 nm in diameter with an inner core containing the viral genome and replicative enzymes. Core morphology is often characteristic for viruses within the same genus. Replication involves reverse transcription and integration into host cell DNA, resulting in a provirus. Integration into germline cells can result in a heritable provirus known as an endogenous retrovirus. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the family , which is available at ictv.global/report/retroviridae.
Topics: Animals; DNA Viruses; Genome, Viral; Host Specificity; Retroviridae; Vertebrates; Virion; Virus Replication
PubMed: 34939563
DOI: 10.1099/jgv.0.001712 -
Critical Reviews in Microbiology Nov 2018The human genome contains a large number of retroviral elements acquired over the process of evolution, some of which are specific to primates. However, as many of these... (Review)
Review
The human genome contains a large number of retroviral elements acquired over the process of evolution, some of which are specific to primates. However, as many of these are defective or silenced through epigenetic changes, they were historically considered "junk DNA" and their potential role in human physiology or pathological circumstances have been poorly studied. The most recently acquired, human endogenous retrovirus-K (HERV-K), has multiple copies in the human genome and some of them have complete open reading frames that are transcribed and translated, especially in early embryogenesis. Phylogenetically, HERV-K is considered a supergroup of viruses. One of the subtypes, termed HML-2, seems to be the most active and hence, it is the best studied. Aberrant expression of HML-2 in adult tissues has been associated with certain types of cancer and with neurodegenerative diseases. This review discusses the discovery of these viruses, their classification, structure, regulation and potential for replication, physiological roles, and their involvement in disease pathogenesis. Finally, it presents different therapeutic approaches being considered to target these viruses.
Topics: Animals; Endogenous Retroviruses; Genome, Human; Humans; Retroviridae; Retroviridae Infections; Virus Replication
PubMed: 30318978
DOI: 10.1080/1040841X.2018.1501345 -
Current Opinion in Virology Jun 2019During retrovirus maturation, cleavage of the precursor structural Gag polyprotein by the viral protease induces architectural rearrangement of the virus particle from... (Review)
Review
During retrovirus maturation, cleavage of the precursor structural Gag polyprotein by the viral protease induces architectural rearrangement of the virus particle from an immature into a mature, infectious form. The structural rearrangement encapsidates the viral RNA genome in a fullerene capsid, producing a diffusible viral core that can initiate infection upon entry into the cytoplasm of a host cell. Maturation is an important therapeutic window against HIV-1. In this review, we highlight recent breakthroughs in understanding of the structures of retroviral immature and mature capsid lattices that define the boundary conditions of maturation and provide novel insights on capsid transformation. We also discuss emerging insights on encapsidation of the viral genome in the mature capsid, as well as remaining questions for further study.
Topics: Capsid; Capsid Proteins; Genome, Viral; HIV-1; Models, Molecular; Peptide Hydrolases; RNA, Viral; Retroviridae; Virion; Virus Assembly
PubMed: 31185449
DOI: 10.1016/j.coviro.2019.05.004 -
Fertility and Sterility May 1989
Topics: Female; Genitalia, Female; HIV Seropositivity; Humans; Male; Reproduction; Reproductive Techniques; Retroviridae; Retroviridae Infections; Semen; Virus Replication
PubMed: 2540047
DOI: 10.1016/s0015-0282(16)60661-1 -
Science (New York, N.Y.) Jun 1988First brought to scientific attention as infectious cancer-causing agents nearly 80 years ago, retroviruses are popular in contemporary biology for many reasons. (i) The... (Review)
Review
First brought to scientific attention as infectious cancer-causing agents nearly 80 years ago, retroviruses are popular in contemporary biology for many reasons. (i) The virus life cycle includes several events--in particular, reverse transcription of the viral RNA genome into DNA, orderly integration of viral DNA into host chromosomes, and utilization of host mechanisms for gene expression in response to viral signals--which are broadly informative about eukaryotic cells and viruses. (ii) Retroviral oncogenesis usually depends on transduction or insertional activation of cellular genes, and isolation of those genes has provided the scientific community with many of the molecular components now implicated in the control of normal growth and in human cancer. (iii) Retroviruses include many important veterinary pathogens and two recently discovered human pathogens, the causative agents of the acquired immunodeficiency syndrome (AIDS) and adult T cell leukemia/lymphoma. (iv) Retroviruses are genetic vectors in nature and can be modified to serve as genetic vectors for both experimental and therapeutic purposes. (v) Insertion of retroviral DNA into host chromosomes can be used to mark cell lineages and to make developmental mutants. Progress in these and other areas of retrovirus-related biology has been enormous during the past two decades, but many practical and theoretical problems remain to be solved.
Topics: Animals; Genes, Viral; Humans; Models, Biological; Research Design; Retroviridae
PubMed: 3287617
DOI: 10.1126/science.3287617 -
Viruses Nov 2021Retroviral infection delivers an RNA genome into the cytoplasm that serves as the template for the synthesis of a linear double-stranded DNA copy by the viral reverse... (Review)
Review
Retroviral infection delivers an RNA genome into the cytoplasm that serves as the template for the synthesis of a linear double-stranded DNA copy by the viral reverse transcriptase. Within the nucleus this linear DNA gives rise to extrachromosomal circular forms, and in a key step of the life cycle is inserted into the host genome to form the integrated provirus. The unintegrated DNA forms, like those of DNAs entering cells by other means, are rapidly loaded with nucleosomes and heavily silenced by epigenetic histone modifications. This review summarizes our present understanding of the silencing machinery for the DNAs of the mouse leukemia viruses and human immunodeficiency virus type 1. We consider the potential impact of the silencing on virus replication, on the sensing of the virus by the innate immune system, and on the formation of latent proviruses. We also speculate on the changeover to high expression from the integrated proviruses in permissive cell types, and briefly consider the silencing of proviruses even after integration in embryonic stem cells and other developmentally primitive cell types.
Topics: Animals; DNA, Viral; Gene Silencing; HIV-1; Histone Code; Humans; Leukemia Virus, Murine; Proviruses; Retroviridae; Transcription, Genetic; Virus Integration; Virus Replication
PubMed: 34835055
DOI: 10.3390/v13112248 -
Virus Research Dec 2004The release of retrovirus particles from the infected cell is greatly stimulated by short motifs, known as "late" or "L" domains, present within the Gag precursor... (Review)
Review
The release of retrovirus particles from the infected cell is greatly stimulated by short motifs, known as "late" or "L" domains, present within the Gag precursor protein. Three distinct classes of L domains have been identified; these bear the core sequence: Pro-Thr/Ser-Ala-Pro [P(T/S)AP], Pro-Pro-x-Tyr (PPxY), or Tyr-Pro-x-Leu (YPxL). A number of recent studies have demonstrated that L domains function by interacting with components of the machinery responsible for sorting cellular proteins into the multivesicular body (MVB) pathway. This review traces the history of L domain discovery and characterization, and highlights the relationship between L domain activity, retrovirus release, and the host endosomal sorting machinery.
Topics: Gene Expression Regulation, Viral; Gene Products, gag; Retroviridae; Ubiquitin; Virus Assembly
PubMed: 15567490
DOI: 10.1016/j.virusres.2004.08.007 -
Cell Aug 1995
Review
Topics: Amino Acid Sequence; Animals; Genetic Vectors; Humans; Leukemia Virus, Gibbon Ape; Molecular Sequence Data; Receptors, Virus; Retroviridae; Retroviridae Infections
PubMed: 7664331
DOI: 10.1016/0092-8674(95)90024-1 -
Viruses Mar 2021I was fortunate to be associated with the lab of Stephen Oroszlan at the US National Cancer Institute from ~1982 until his conversion to Emeritus status in 1995. His lab...
I was fortunate to be associated with the lab of Stephen Oroszlan at the US National Cancer Institute from ~1982 until his conversion to Emeritus status in 1995. His lab made groundbreaking discoveries on retroviral proteins during that time, including many features that could not have been inferred or anticipated from straightforward sequence information. Building on the Oroszlan lab results, my colleagues and I demonstrated that the zinc fingers in nucleocapsid proteins play a crucial role in genomic RNA encapsidation; that the N-terminal myristylation of the Gag proteins of many retroviruses is important for their association with the plasma membrane before particle assembly is completed; and that gammaretroviruses initially synthesize their Env protein as an inactive precursor and then truncate the cytoplasmic tail of the transmembrane protein, activating Env fusogenicity, during virus maturation. We also elucidated several aspects of the mechanism of translational suppression in gene expression in gammaretroviruses; amazingly, this is a fundamentally different mechanism of suppression from that in most other retroviral genera.
Topics: Cell Membrane; History, 21st Century; Retroviridae; Viral Proteins
PubMed: 33809689
DOI: 10.3390/v13030491 -
Viruses Sep 2019It has now been more than two years since we said our last goodbye to Jan Svoboda (14 [...].
It has now been more than two years since we said our last goodbye to Jan Svoboda (14 [...].
Topics: Humans; Retroviridae; Retroviridae Infections
PubMed: 31491994
DOI: 10.3390/v11090828