[Home] [ICTV Taxonomy - Index of Viruses] [Virus Descriptions] [Character List] [Picture Gallery]
[Tutorial] [Online Data Retrieval & Identification] [Virus Isolate Registration & Submission] [Search]
Descriptions are generated automatically from the ICTVdB database including links. Some descriptions are only very basic and links may point to documents that are not yet published on the Web.

00.003. Arenaviridae

Cite this publication as: ICTVdB Management (2006). 00.003. Arenaviridae. In: ICTVdB - The Universal Virus Database, version 3. Büchen-Osmond, C. (Ed), Columbia University, New York, USA

Cite this site as: ICTVdB - The Universal Virus Database, version 4. http://www.ncbi.nlm.nih.gov/ICTVdb/ICTVdB/

Table of Contents

Classification

This is a description of a vertebrate virus at the family level.

ICTVdB Virus Code: 00.003. Virus accession number: 00003FAM. Obsolete virus code: 03.; superceded accession number: 03000000.
NCBI Taxon Identifier NCBI Taxonomy ID: 11617.

Virion Properties

Morphology

Virions consist of an envelope and a nucleocapsid. Virus capsid is enveloped. Virions are spherical to pleomorphic measuring (50-)110-130(-300) nm in diameter. The envelope surrounds probably two nucleocapsids; has surface projections. Surface projections are distinctive club-shaped peplomers that are spaced widely apart and covering evenly the surface; embedded in a lipid bilayer which is comprises surface glycoproteins (GP). Surface projections are composed of one type of protein. Surface projections are 8-10 nm long. Host ribosomes are seen inside the envelope (in varying numbers). Capsid/nucleocapsid is elongated with helical symmetry. Virions consist of two nucleocapsids. The nucleocapsid is filamentous and forming a closed circle; has a "string of beads" appearance; with a varying length with a length of 1000-1300 nm (L segment, 450-640 nm (S segment) and a width of 3-4 nm. Nucleocapsid contains a polymerase complex and a nucleoprotein complex. Nucleocapsids are organized in closed circles and display a linear array of nucleosomal subunits (when they are isolated and free of contaminating host ribosomes).

Physicochemical and Physical Properties

Virions have a buoyant density in CsCl of 1.19-1.2 g cm-3; sucrose of 1.17-1.18 g cm-3; amidotrizoate compounds of 1.14 g cm-3. The sedimentation coefficient is 325-500 S20w. The thermal inactivation point (TIP) is at 56°C. Under in vitro conditions virions are stable when stored at -70°C; inactivated in acid environment of pH 5.5 (and below, inactivated in alkaline environment of pH 8.5 (and above). Virions are sensitive to treatment with organic solvents (and infectivity is inactivated). The infectivity is reduced after exposure to irradiation (UV and gamma-irradiation).

Nucleic Acid

The Mr of the genome constitutes 2% of the virion by weight. The genome is segmented and consists of two segments of linear, negative-sense to ambisense, single-stranded RNA. The genome is transcriptional inactive. Minor species of non-genomic nucleic acid are also found in virions. The encapsidated nucleic acid is mainly of genomic origin, but virions may also contain subgenomic RNA and nucleic acid of host origin including three molecules of host rRNA (of cellular origin with sedimentation coefficients of 28S, 18S and 4-6S and three subgenomic mRNA (species presumably associated with encapsidated ribosomes) derived from genomic S RNA (for the precursor of protein N and the precursor of protein GPC), or L RNA (for the Z protein). RNA segments are not homologous. The complete genome is about 10000-11000 nucleotides long. The genome has a guanine + cytosine content of 40-45 %. The genome has a virus coded terminal protein which is circular, but not covalently closed. Nucleotide sequences at the 3'-terminus are largely complementary to similar regions on the 5' end. The 5'-end of the genome does not have cap. The 3'-terminus has conserved nucleotide sequences; in all segments and species of same genus; sequence has 19-30 nucleotides in length; in S RNA. The intergenic region has S a hairpin configuration (potential depending on virus). The multipartite genome is encapsidated, each segment in a separate nucleocapsid, and the nucleocapsids are surrounded by one envelope. Each virion contains multiple copies of the genome; often segments of the genome in non-equimolar proportions (due to frequent packaging of S RNA strands).

GenBank records for nucleotide sequences; complete genome sequences.

Proteins

Proteins constitute about 70% of the particle weight.

The viral genome encodes structural proteins and non-structural proteins. Virions consist of 5 structural protein(s) located in the envelope and ribonucleoprotein complex.

Structural Proteins: Envelope protein GPC has a molecular mass of 75000-76000 Da. Envelope protein has a function assigned; is formation of tetrameric forming the viral spikes (GP-1 and GP-2, during post-translational processing envelope protein has been cleaved from the precursor protein (into GP-1 (G1) and GP-2 (G2), during post-translational processing envelope protein modifications occur that include glycosylation. Envelope protein GP-1 or G1; has a molecular mass of 44000 Da; is interacting with viral receptors; which possess(es) virus neutralization activity; during post-translational processing envelope protein modifications occur that include glycosylation. Envelope protein GP-2 or G2 has a molecular mass of 34000-44000 Da; is involved in membrane fusion for viral entry (which is acid dependent (pH 4.5-5.5), during post-translational processing envelope protein modifications occur that include glycosylation. Nucleocapsid protein N or NP; has a molecular mass of 63000-72000 Da; is binding to the genomic RNA and forming a ribonucleoprotein complex. Nucleocapsid protein Z or p11; has a molecular mass of 10000-14000 Da; is a putative zinc binding protein and forming an internal structural component.

Non-Structural Proteins: 3-4 non-structural protein(s) are found. The virus codes for enzymes and genome associated polypeptides; an RNA-dependent RNA polymerase. In addition to the polymerase, the virus codes for enzymes such as transcriptase, replicase, proteinase (poly(U) and poly(A) polymerases, 1 internal protein(s). Non-structural protein L protein, an RNA dependent RNA polymerase; has a molecular mass of 25 kDa.

Lipids

Lipids are present and located in the envelope. Virions are composed of 20% lipids by weight. The composition of viral lipids and host cell membranes are similar. The lipids are of host origin and are derived from plasma membranes.

Carbohydrates

Carbohydrates are found in virions; constitute 8% of virion dry weight; are present as glycoproteins; are complex glycans.




















Arenavirus genome map.

Genome Organization and Replication

Virions attach to undefined receptors to enter host cells via the endosomal route.

The process of intracellular uncoating of virions occurs in the cytoplasm and the viral nucleic acid is delivered to the cell cytoplasm, the site of mRNA transcription.

Transcription: Virus transcription is temporally regulated. Early genes are expressed during genome uncoating. Non-structural proteins involved in transcription. The viral genome is transcribed from the viral sense strand from the 3' end, or from the 5' end.

The viral genome is transcribed by a viral RNA-dependent RNA polymerase into 2 mRNA(s) (N and L mRNA). The transcribed mRNAs are subgenomic in a viral-complementary sense. Viral mRNA(s) is/are transcribed with no overlaps; in an ambisense coding arrangement; synthesized from all RNA segments.

Specific termination sequences have been identified. Termination is caused by characteristic GC-rich, strongly base-paired stem loop-structure.

Coding Strategy of Segment 1: RNA-L exhibits an ambisense coding strategy. That encode(s) structural proteins. Encodes 2 structural protein(s), namely a polymerase complex (L protein, and Z protein). Structural proteins are encoded in the viral-complementary sense sequence.

Coding Strategy of Segment 2: RNA-S. Exhibits an ambisense coding strategy. Contains 2 ORF(s). Encode(s) structural proteins. Encodes 2 structural protein(s). The sequence encodes GPC a glycoprotein precursor and a non-glycosylated polypeptide (N). The sequence encodes GPC. Structural proteins are encoded in the viral sense sequence. Part of sequence. Acts as a template for synthesis of viral mRNA. A non-glycosylated polypeptide. N. Translational units do not overlap. Sequence has a. Intergenic non-coding region can form hairpin configuration(s).

Translation: Envelope glycoproteins. Are modified by post-translational processes. Are processed to contain complex glycans. Including proteolytic cleavage. Post-translational processes occur during transport. To the plasma membrane.

The genome replicates in the cytoplasm. Genome replication involves RNA-directed RNA synthesis; occurs through a single stranded replicative intermediate involving a rolling circle mechanism. The rolling circle mechanism generates complementary intermediate forms referred to as the antigenome. The process of genome replication may involve a slippage mechanism during initiation of transcription termination signals. At an early stage, templates are involved in the sysnthesis of a full-length RNA replication. Replication in vitro is sensitive to amantadine, alpha-amanitin, glucosamine, and thiosemicarbazones.

Replication cycle The virus has the ability to form gene reassortment. Gene reassortment occurs during mixed infections; involving virus of the same strain; involving virus from a different species; but not between a different; species. Reassortment includes genomic sequence segments that are diploid, or multiploid.

The precursor of envelope protein is found in the infected cell cytoplasm. Viral proteins accumulate in the cytoplasm. Virions accumulate in the cell cytoplasm.

Assembly and Egress: Capisd proteins assemble with viral nucleic acid to form the virion. Viruses assemble at the cell membrane.

Maturation: Virions mature by budding through and by fusion with plasma membranes on the cell surface in the vicinity of ribosomes in the cytoplasm.

Release: Host cells remain intact. Virus is released from host cell by budding through the cell membrane; and acquisition of an envelope. Virus is released from host cell without causing death. The virus envelope is acquired from the host cell by budding off the cell membrane and is assembled in the cytoplasm.

Antigenicity

Antigenic determinants may be found on virion surfaces and nucleocapsids and correspond to each of the major structural proteins and structural glycoproteins. Although different antigenic determinants have different specificities, the antigenic determinants are in general serogroup-specific. Antigenic determinants that possess type-specific reactivity are found on the peplomers of envelope. The type-specific antigenic determinants are involved in antibody mediated neutralization. Antigenic determinants that possess serogroup-specific reactivity are found on the nucleocapsids. The serogroup-specific antigenic determinants are involved in antibody mediated complement fixation. Antigenic specificity of the virion can be determined by neutralization tests, or complement fixation tests.

The following proteins share common sequences and epitopes nucleocapsid proteins (N). Proteins have all epitopes in common with proteins from other species. Cross-reactivity is found. Cross-reactivity between species of the same serotype, but not with species of another serotype. Protective immunity is induced in the form of neutralizing antibodies. The virus induces the formation of neutralizing antibodies. Antibody response that is protective against infection is usually directed against virion glycoproteins. The virus serotype is determined by a complement fixation test; using monoclonal antibodies and polyclonal antibodies. Antigenic distances between individual species, expressed as serological indices, are correlated with the degree of sequence difference in their surface glycoprotein. Species that are serologically interrelated have antigenic homologies with different serogroups of the same genus. Although the degree of antigenic specificity varies with the degree of relatedness, the antigenicity is distinct from species of the same serogroup. Most species in the genus are related antigenically. They are sharing some epitopes in the envelope proteins. Serological analyses show distant or no relationship between viruses originating from different continents. Serological analyses show close interrelationship between viruses originating from the same continent. Sequence homologies more than 50% between species.

Biological Properties

Natural Host

Virus infects during its life cycle a variety of vertebrate hosts. Virus has an enzootic cycle and is transmitted from rodents to humans, or rodents to other vertebrates. Domain Viral hosts belong to the Domain Eucarya.

Domain Eucarya
Kingdom Animalia.

Kingdom Animalia
Phylum Chordata.

Phylum Vertebrata
Subphylum Vertebrata; Class Mammalia.

Class Mammalia Order Rodentia and Primates;
Family Hominidae.
Virus infects Homo sapiens (human, Suborder Sciurognathi; Family Muridae; Subfamily Murinae; virus infects Genus Mus musculus (mouse).

Ecology, Epidemiology and Control

A fact sheet on this virus is available from the Centers for Disease Control and Prevention (CDC), National Center for Infectious Diseases (NCID) (Arenavirus and at Ciencia Hoy).

Taxonomic Structure of the Family

00.003.0.01. Arenavirus.

Data Sources and Contributions

The description has been compiled from data in the ICTV Report presented by Buchmeier MJ, Clegg JCS, Franze-Fernandez MT, Kolakofsky D, Peters CJ, Southern PJ.

References

Medline References.

The following generic references are cited in the most recent ICTV Report.

PubMed References.



Limit search to: Title & Body Title Document Path
Show Reverse Sort

DELTA - DEscription Language for TAxonomy developed by Dr Mike Dallwitz, Toni Paine and Eric Zurcher, CSIRO Entomology, Canberra, Australia. ICTVdB - The Universal Virus Database, developed for the International Committee on Taxonomy of Viruses by Dr Cornelia Büchen-Osmond is written in DELTA. The virus descriptions in ICTVdB are coded by, or using data from experts in the field of virology or members ICTV. The character list is the underlying code. All virus descriptions are based on the character list and natural language translations are automatically generated and formatted for display on the Web from the descriptions in DELTA-format. The description has been generated automatically from DELTA files. DELTA - DEscription Language for TAxonomy developed by Dr Mike Dallwitz, Toni Paine and Eric Zurcher, CSIRO Entomology, Canberra, Australia.

ICTVdB - The Universal Virus Database, developed for the International Committee on Taxonomy of Viruses (ICTV) by Dr Cornelia Büchen-Osmond, is written in DELTA. The virus descriptions in ICTVdB are coded by ICTV members and experts, or by the ICTVdB Management using data provided by the experts, the literature or the latest ICTV Report. The character list is the underlying code. All virus descriptions are based on the character list and natural language translations from the encoded descriptions are automatically generated and formatted for display on the Web.

Developer of the DELTA software: M. J. Dallwitz, T. Paine and E. Zurcher

ICTVdB and DELTA related References

Comments to ICTVdB Management
Last updated on 25 April 2006 by Cornelia Büchen-Osmond
Copyright © 2002    International Committee on Taxonomy of Viruses.    All rights reserved.


Additional access points to virus species lists, descriptions and images on the web:

Species catalogue                     iSpecies.org - a species search engine           a species search engine

Google Analytics      Google Analytics: activity view