Mononegavirales

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Mononegavirales
Vesicular stomatitis virus (VSV) virion and Mononegavirales genomes
Virus classification Edit this classification
(unranked): Virus
Realm: Riboviria
Kingdom: Orthornavirae
Phylum:
Negarnaviricota
Class: Monjiviricetes
Order: Mononegavirales
Families

see text

Mononegavirales is an order of

measles virus, mumps virus, Nipah virus, and rabies virus. Important pathogens of nonhuman animals and plants are also in the group. The order includes eleven virus families: Artoviridae, Bornaviridae, Filoviridae, Lispiviridae, Mymonaviridae, Nyamiviridae, Paramyxoviridae, Pneumoviridae, Rhabdoviridae, Sunviridae, and Xinmoviridae.[1]

Use of term

The order Mononegavirales (pronounced: /ˌmɒnəˌnɛɡəviˈrɑːlɪz/ MON-ə-NEG-ə-vee-RAH-liz) [note 1][2][3] is a virological taxon that was created in 1991[4][5] and amended in 1995,[6] 1997,[7] 2000,[8] 2005,[9] 2011,[2] 2016,[10] 2017,[11] and 2018.[1] The name Mononegavirales is derived from the Ancient Greek adjective μóνος monos (alluding to the monopartite and single-stranded genomes of most mononegaviruses), the Latin verb negare (alluding to the negative polarity of these genomes), and the taxonomic suffix -virales (denoting a viral order).[3]

Order inclusion criteria

The genome organization and RNA synthesis of order Mononegavirales

A virus is a member of the order Mononegavirales if[2][3]

  • its genome is a linear, typically (but not always) nonsegmented, single-stranded, non-infectious RNA of negative polarity; possesses inverse-complementary 3' and 5' termini; and is not covalently linked to a protein;
  • its genome has the characteristic gene order 3'-UTR–core protein genes–envelope protein genes–RNA-dependent RNA polymerase gene–5'-UTR (3'-N-P-M-G-L-5') (there are, however, some exceptions);
  • it produces 5–10 distinct
    5' capped and polyadenylated
    ;
  • it replicates by synthesizing complete antigenomes;
  • it forms infectious helical ribonucleocapsids as the templates for the synthesis of mRNAs, antigenomes, and genomes;
  • it encodes an RNA-dependent RNA polymerase (RdRp, L) that is highly homologous to those of other mononegaviruses; and/or
  • it typically (but not always) produces enveloped virions with a molecular mass of 300–1,000×106; an S20W of 550–>1,045; and a buoyant density in CsCl of 1.18–1.22 g/cm3.

Life cycle

Life cycle of vesiculoviruses

The mononegavirus

mRNAs, which are then translated into structural and nonstructural proteins.[9]

Mononegavirus RdRps bind to a single

promoter located at the 3' end of the genome. Transcription either terminates after a gene or continues to the next gene downstream. This means that genes close to the 3' end of the genome are transcribed in the greatest abundance, whereas those toward the 5' end are least likely to be transcribed. The gene order is therefore a simple but effective form of transcriptional regulation. The most abundant protein produced is the nucleoprotein, whose concentration in the cell determines when the RdRp switches from gene transcription to genome replication.[9]

Replication results in full-length, positive-stranded antigenomes that are in turn transcribed into negative-stranded virus progeny genome copies. Newly synthesized structural proteins and genomes self-assemble and accumulate near the inside of the cell membrane. Virions bud off from the cell, gaining their envelopes from the cellular membrane they bud from. The mature progeny particles then infect other cells to repeat the cycle.[9]

Paleovirology

Mononegaviruses have a history that dates back several tens of million of years. Mononegavirus "

fossils" have been discovered in the form of mononegavirus genes or gene fragments integrated into mammalian genomes. For instance, bornavirus gene "fossils" have been detected in the genomes of bats, fish, hyraxes, marsupials, primates, rodents, ruminants, and elephants.[12][13][14][15][16] Filovirus gene "fossils" have been detected in the genomes of bats, rodents, shrews, tenrecs, and marsupials.[13][14][17][18] A Midway virus "fossil" was found in the genome of zebrafish.[13] Finally, rhabdovirus "fossils" were found in the genomes of crustaceans, mosquitoes, ticks, and plants.[19][14][20][21]

Taxonomy

Mononegavirales phylogenetic tree

The order has eleven families that include numerous genera, which consist of many different species:[citation needed]

Table of the order showing all families, genera, species, and their viruses:[1]

Table legend: "*" denotes type species.

Notes

  1. ^ According to the rules for taxon naming established by the International Committee on Taxonomy of Viruses (ICTV), the name Mononegavirales is always to be capitalized, italicized, and never abbreviated. The names of the order's physical members ("mononegaviruses" or "mononegavirads") are to be written in lower case, are not italicized, and used without articles.

References

  1. ^
    PMID 29637429
    .
  2. ^
    ISBN 978-0-12-384684-6
    .
  3. ^
    PMID 21046175
    .
  4. S2CID 312908
    .
  5. ISBN 978-0-387-82286-0
    .
  6. ISBN 978-3-211-82594-5
    .
  7. PMID 9672597
    .
  8. ISBN 978-0-12-370200-5
    .
  9. ^
    ISBN 978-0-12-370200-5
    .
  10. PMID 27216929
    .
  11. PMID 28389807
    .
  12. PMID 20054395
    .
  13. ^
    PMID 20686665
    .
  14. ^
    PMID 21124940
    .
  15. PMID 26569285
    .
  16. S2CID 4776419
    .
  17. PMID 20569424
    .
  18. PMID 22093762
    .
  19. PMID 26388953
    .
  20. PMID 21779172
    .
  21. PMID 21917725
    .

External links
Retrieved from "https://en.wikipedia.org/w/index.php?title=Mononegavirales&oldid=1209768770"