Bocavirus
| Bocavirus | |
|---|---|
| Virus classification | |
| Group: | Group II (ssDNA) |
| Family: | Parvoviridae |
| Subfamily: | Parvovirinae |
| Species | |
|
Bovine bocavirus | |
Bocavirus is a genus in the family Parvoviridae, subfamily Parvovirinae.
The type species is Bovine parvovirus.
History
Bocaviruses were first described in animals in the early 1960s.
Genome
Like the other members of this family, bocaviruses have two open reading frames - ORF1 and 2. Unique among parvoviruses, the bocaviruses contain a third open reading frame between non-structural and structural coding regions.[1] This gene encodes a highly phosphorylated nonstructural protein (NP1) whose function is not yet understood.
ORF1 is a nonstructural protein that is involved in the viral genome replication. ORF2 encodes the two capsid proteins - VP1 and VP2.
Like other parvoviruses, the VP1 unique region contains a putative secretory phospholipase A(2) motif with a conserved Histadine-Aspartic acid-XXY motif in the catalytic center.[2]
Taxonomy
The ICTV criteria for classification of bocaviruses require that
- members of each species are probably antigenically distinct
- natural infection is confined to a single host species
- species are defined as <95% homologous in nonstructural gene DNA sequence
Virology
Bovine bocaviruses utilise endocytosis in clathrin-coated vesicles to enter cells; they are dependent upon acidification, and appear to be associated with actin and microtubule dependency.[3]
An additional protein has been discovered in Canine minute virus. The viral NP1 is required for the read through of an internal polyadenylation site.[4]
Clinical
These viruses generally infect the gastrointestinal and respiratory tracts. Some may cross the placenta and cause congenital infection of the fetus.
Canine minute virus, first isolated in 1967 and associated with disease in 1970, causes respiratory disease with breathing difficulty and enteritis with severe diarrhoea, spontaneous abortion of fetuses, and death of newborn puppies.
Human bocaviruses were first isolated in 2005 in Sweden.[5] They may be able to cause hepatitis in an immunosuppressed host.[6]
Bocaviruses have been isolated from human colon and lung cancers.[7] The clinical importance of this finding - if any - remains to be seen.
The incidence of bocavirus in patients with cancer is higher than that of health controls.[8]
Structure
Like other parvoviruses, bocavirus has an icosohedral structure. The capsid is composed of 60 copies of up to six types of capsid proteins (called VP1 through to VP6) which share a common C-terminal region. The structure of a capsid composed only of VP2 protein was worked out with electron microscopy.[9]
References
- ↑ Manteufel J, Truyen U (2008) Animal bocaviruses: a brief review. Intervirology 51: 328–334.
- ↑ Qu XW, Liu WP, Qi ZY, Duan ZJ, Zheng LS, Kuang ZZ, Zhang WJ, Hou YD (2008) Phospholipase A2-like activity of human bocavirus VP1 unique region. Biochem Biophys Res Commun 365(1):158-163
- ↑ Dudleenamjil E, Lin CY, Dredge D, Murray BK, Robison RA, Johnson FB (2010) Bovine parvovirus uses clathrin-mediated endocytosis for cell entry. J Gen Virol 91(12):3032-3041
- ↑ Sukhu L, Fasina O, Burger L, Rai A, Qiu J, Pintel DJ (2012) Characterization of the non-structural proteins of the bocavirus minute virus of canine (MVC). J Virol
- ↑ Allander T, Tammi MT, Eriksson M, Bjerkner A, Tiveljung-Lindell A, Andersson B (2005) Cloning of a human parvovirus by molecular screening of respiratory tract samples. Proc Natl Acad Sci U S A 102(36):12891-12896
- ↑ Kainulainen L, Waris M, Söderlund-Venermo M, Allander T, Hedman K, Ruuskanen O (2008) Hepatitis and human bocavirus primary infection in a child with T-cell deficiency. J Clin Microbiol 46(12):4104-4105
- ↑ Schildgen V, Malecki M, Tillmann RL, Brockmann M, Schildgen O (2013) The human bocavirus is associated with some lung and colorectal cancers and persists in solid tumors. PLoS One 8(6):e68020
- ↑ Li Y, Dong Y, Jiang J, Yang Y, Liu K, Li Y (2012) High prevelance of human parvovirus infection in patients with malignant tumors. Oncol Lett 3(3):635-640
- ↑ Gurda BL, Parent KN, Bladek H, et al. (June 2010). "Human bocavirus capsid structure: insights into the structural repertoire of the parvoviridae". J. Virol. 84 (12): 5880–9. doi:10.1128/JVI.02719-09. PMC 2876641. PMID 20375175.