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Semotivirus

Semotivirus
Virus classification Edit this classification
(unranked): Virus
Realm: Riboviria
Kingdom: Pararnavirae
Phylum: Artverviricota
Class: Revtraviricetes
Order: Ortervirales
Family: Belpaoviridae
Genus: Semotivirus
Species

See text

Semotivirus is the only genus of viruses in the family Belpaoviridae (formerly included in the family Metaviridae).[1] Species exist as retrotransposons in a eukaryotic host's genome. BEL/pao transposons are only found in animals. Semotivirus is the only genus currently recognized, the genus description corresponds to the family, Belpaoviridae description.[2]

Classification

The lone genus in the family, Semotivirus, was formerly included in the Metaviridae family but was removed due to its paraphyletic relationship to other Metaviridae genera. There is a good chance that more species and genera will be added to the family Belpaoviridae in the future, given the diversity of belpaovirids that is already recognized. The Pol domain order of the families Belpaoviridae, Metaviridae, and Retroviridae is the same within the order Ortervirales, however the integrase is either lacking in the case of the Caulimoviridae or positioned upstream of the protease domain in the case of the Pseudoviridae.[3]

The genus is made up of long terminal repeat (LTR) retrotransposons, also referred to as metazoan-infecting reverse transcriptase viruses.[4]

Composition

The genomic arrangement of members of the Belpaoviridae family is similar to that of long terminal repeat (LTR) retrotransposons of the Metaviridae family.[5] The entire genome is 4.2–10 kb, and one to three genes (pol, env, and gag) are flanked by LTRs of 0.2–1.2 kb.[6] A non-coding region that represents the initial segment of the reverse-transcribed genome is located downstream of the 5′-LTR. This is followed by an 18 nt primer-binding site that is complementary to a certain area inside the 3′-end of a host tRNAArg or a tRNAGly.

Priming the synthesis of the proviral DNA strand is a polypurine tract of approximately 10 nt located upstream of the 3′-LTR. Gag and Pol polyproteins can be encoded by one continuous gene or by two overlapping genes.[7] These genes encode the capsid and nucleocapsid domains, as well as the protease, reverse transcriptase (RT), ribonuclease H, and integrase domains.

Replication

Few information is known about the virion morphology of belpaovirids. The virion morphology of semotivirus is poorly understood. However, belpaovirids most likely replicate by forming virus-like particles (VLPs), just like retrovirids, metavirids, and pseudovirids do, since they encode a Gag polyprotein with nucleocapsid and capsid protein domains homologous to those of other members of the order Ortervirales.[8][9] An env-like gene is present in certain belpaovirids, however its exact role is still unknown.[10]

Although the details of replication are not well known, it is thought to resemble that of members of the Metaviridae family,[11] in which RT mediates the conversion of a full transcript into a dsDNA that is incorporated into the host genome by the integrase protein. After the integrated provirus has been transcribed by the host RNA polymerase II, new virus RNAs are created, which the matching host enzymes cap and polyadenylate. Once in the host cell's cytoplasm, these fresh viral RNAs are translated into immature VLPs by Gag and Pol. VLP maturation is the end outcome of the viral protease's proteolytic processing of the polyproteins. The new viral RNAs are then reverse-transcribed by RT into dsDNA molecules, which are then sent back to the nucleus and inserted into fresh locations within the host cell genome.[12]

RT: Reverse Transcripase.

VLPS: Virus-Like Particle.

LTRs: Long Terminal Repeat.

Species

Full-length genome architectures of representative semotiviruses.

The genus contains the following species:[13]

  • Anopheles gambiae Moose virus
  • Antheraea semotivirus Tamy
  • Ascaris lumbricoides Tas virus
  • Bombyx mori Pao virus
  • Caenorhabditis elegans Cer13 virus
  • Drosophila melanogaster Bel virus
  • Drosophila melanogaster Roo virus
  • Drosophila semotivirus Max
  • Drosophila simulans Ninja virus
  • Schistosoma semotivirus Sinbad
  • Takifugu rubripes Suzu virus

References

  1. ^ Krupovic, M; Blomberg, J; Coffin, JM; Dasgupta, I; Fan, H; Geering, AD; Gifford, R; Harrach, B; Hull, R; Johnson, W; Kreuze, JF; Lindemann, D; Llorens, C; Lockhart, B; Mayer, J; Muller, E; Olszewski, N; Pappu, HR; Pooggin, M; Richert-Pöggeler, KR; Sabanadzovic, S; Sanfaçon, H; Schoelz, JE; Seal, S; Stavolone, L; Stoye, JP; Teycheney, PY; Tristem, M; Koonin, EV; Kuhn, JH (4 April 2018). "Ortervirales: A new viral order unifying five families of reverse-transcribing viruses". Journal of Virology. 92 (12). doi:10.1128/JVI.00515-18. PMC 5974489. PMID 29618642.
  2. ^ "Genus: Semotivirus | ICTV". ictv.global. Retrieved 2024-10-13.
  3. ^ Llorens, Carlos; Soriano, Beatriz; Krupovic, Mart; ICTV Report Consortium (2021). "ICTV Virus Taxonomy Profile: Pseudoviridae". Journal of General Virology. 102 (3): 001563. doi:10.1099/jgv.0.001563. ISSN 1465-2099. PMC 8515867. PMID 33528349.
  4. ^ Soriano, Beatriz; Krupovic, Mart; Llorens, Carlos (2021). "ICTV Virus Taxonomy Profile: Belpaoviridae 2021". Journal of General Virology. 102 (11): 001688. doi:10.1099/jgv.0.001688. ISSN 1465-2099. PMC 8742986. PMID 34761738.
  5. ^ Llorens, Carlos; Soriano, Beatriz; Krupovic, Mart; ICTV Report Consortium (2020). "ICTV Virus Taxonomy Profile: Metaviridae". Journal of General Virology. 101 (11): 1131–1132. doi:10.1099/jgv.0.001509. ISSN 1465-2099. PMC 7879559. PMID 33048045.
  6. ^ Llorens, C.; Futami, R.; Covelli, L.; Dominguez-Escriba, L.; Viu, J. M.; Tamarit, D.; Aguilar-Rodriguez, J.; Vicente-Ripolles, M.; Fuster, G.; Bernet, G. P.; Maumus, F.; Munoz-Pomer, A.; Sempere, J. M.; Latorre, A.; Moya, A. (2010-10-29). "The Gypsy Database (GyDB) of mobile genetic elements: release 2.0". Nucleic Acids Research. 39 (Database): D70–D74. doi:10.1093/nar/gkq1061. ISSN 0305-1048. PMC 3013669. PMID 21036865.
  7. ^ Massimiliano Marsano, Renè; Caizzi, Ruggiero (2005-09-12). "A genome-wide screening of BEL-Pao like retrotransposons in Anopheles gambiae by the LTR_STRUC program". Gene. 357 (2): 115–121. doi:10.1016/j.gene.2005.06.010. ISSN 0378-1119. PMID 16102916.
  8. ^ Krupovic, Mart; Blomberg, Jonas; Coffin, John M.; Dasgupta, Indranil; Fan, Hung; Geering, Andrew D.; Gifford, Robert; Harrach, Balázs; Hull, Roger; Johnson, Welkin; Kreuze, Jan F.; Lindemann, Dirk; Llorens, Carlos; Lockhart, Ben; Mayer, Jens (2018-06-15). "Ortervirales: New Virus Order Unifying Five Families of Reverse-Transcribing Viruses". Journal of Virology. 92 (12). doi:10.1128/JVI.00515-18. ISSN 0022-538X. PMC 5974489. PMID 29618642.
  9. ^ Krupovic, Mart; Koonin, Eugene V. (2017-06-15). "Homologous Capsid Proteins Testify to the Common Ancestry of Retroviruses, Caulimoviruses, Pseudoviruses, and Metaviruses". Journal of Virology. 91 (12). doi:10.1128/JVI.00210-17. ISSN 0022-538X. PMC 5446648. PMID 28356531.
  10. ^ de la Chaux, Nicole; Wagner, Andreas (2011-06-04). "BEL/Pao retrotransposons in metazoan genomes". BMC Evolutionary Biology. 11 (1): 154. Bibcode:2011BMCEE..11..154D. doi:10.1186/1471-2148-11-154. ISSN 1471-2148. PMC 3118150. PMID 21639932.
  11. ^ Llorens, Carlos; Soriano, Beatriz; Krupovic, Mart; ICTV Report Consortium (2020). "ICTV Virus Taxonomy Profile: Metaviridae". Journal of General Virology. 101 (11): 1131–1132. doi:10.1099/jgv.0.001509. ISSN 1465-2099. PMC 7879559. PMID 33048045.
  12. ^ Soriano, Beatriz; Krupovic, Mart; Llorens, Carlos (2021). "ICTV Virus Taxonomy Profile: Belpaoviridae 2021". Journal of General Virology. 102 (11). doi:10.1099/jgv.0.001688. PMC 8742986. PMID 34761738.
  13. ^ "Virus Taxonomy: 2020 Release". International Committee on Taxonomy of Viruses (ICTV). Retrieved 7 July 2021.
  • Frame IG, Cutfield JF, Poulter RTM (2001) New BEL-like LTR-retrotransposons in Fugu rubripes, Caenorhabditis elegans, and Drosophila melanogaster. Gene 263(1–2):219–230


Quelle: http://en.wikipedia.org/wiki/Belpaoviridae