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00.003.0.01. Arenavirus
Cite this publication as: ICTVdB Management (2006).
00.003.0.01. Arenavirus. In: ICTVdB - The Universal Virus Database,
version 4. 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/
This is a description of a
vertebrate virus at the genus level.
ICTVdB Virus Code: 00.003.0.01. Virus accession number:
003001GE. Obsolete virus code: 03.0.1.; superceded accession number: 03010000.
NCBI Taxon Identifier NCBI Taxonomy ID:
11618.
Name, Synonyms and Lineage
Synonym(s): LCM virus
group. Virus is of the family 00.003.
Arenaviridae.
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 isolated
nucleocapsids, free of contaminating host ribosomes organized in closed circles
and display a linear array of nucleosomal subunits.
Diagram and electron micrograph of arenavirus.
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).
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, virions may contain three
subgenomic nucleic acid species; virions may contain mRNA
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
RNA-L is sequenced and complete
sequence is about 7400 nucleotides long. RNA-S is is about about 3400 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
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 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 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: The viral genome is
transcribed by a viral RNA-dependent RNA polymerase into 2 mRNAs (N
and L mRNA). The transcribed mRNAs are subgenomic in a viral-complementary
sense.
Sequence homologies more
than 50% between species.
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).
A fact
sheet on this virus is available from the Centers for Disease Control and
Prevention (CDC), National Center for Infectious Diseases (NCID).
Type species 00.003.0.01.001.
Lymphocytic choriomeningitis virus
.
List of Species in the
Genus.
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.
Medline References.
The following generic references are cited in the most
recent ICTV Report.
PubMed References.