title: Evidence of apoptosis induced by viral protein 2 of chicken anaemia virus.
abstract: Although viral protein 3 (VP3) of chicken anaemia virus (CAV) has been well recognised as an inducer of apoptosis, viral protein 2 (VP2) of the virus has only been speculated to have apoptotic activity. This has not been verified because the open reading frame (ORF) encoding VP2 completely encompasses that encoding VP3, and thus the possibility of expression of VP3 cannot be excluded. The aim of this study was to elucidate the potential role of VP2 as an inducer of apoptosis. Site-directed mutagenesis was used to generate a point mutation that knocked out VP3 by early termination of its translation with a stop codon without imposing any change in the amino acid sequence of VP2. The mutated sequence was inserted into the pCAT plasmid preceded by a favorable Kozak's consensus sequence to create pCAT-VP2(+)VP3(-). The absence of VP3 expression in MSB1 cells transfected with this plasmid was confirmed using Western blotting, and DNA strand breaks and nuclear morphological changes were assessed to detect apoptosis. There was an increased level of apoptotic death in cells transfected with pCAT-VP2(+)VP3(-) compared to those transfected with the vector alone. This provides evidence that CAV VP2 can induce apoptosis.
authors.affiliation: Department of Poultry Viral Vaccine Prodution and Research, Razi Vaccine and Serum Research Institute, Karaj, Iran. amkaffashi@yahoo.com.
authors.forename: Amir
authors.initials: A
authors.lastname: Kaffashi
authors.affiliation: Department of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia.
authors.forename: Charles N
authors.initials: CN
authors.lastname: Pagel
authors.affiliation: Department of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia.
authors.forename: Amir H
authors.initials: AH
authors.lastname: Noormohammadi
authors.affiliation: Department of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia.
authors.forename: Glenn F
authors.initials: GF
authors.lastname: Browning
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis; D001483:Base Sequence; D036022:Capsid Proteins / Q000235:genetics / Q000378:metabolism*; D017727:Chicken anemia virus / Q000235:genetics / Q000378:metabolism*; D002645:Chickens; D018173:Circoviridae Infections / Q000503:physiopathology / Q000662:veterinary* / Q000821:virology; D008969:Molecular Sequence Data; D011201:Poultry Diseases / Q000503:physiopathology* / Q000821:virology
chemical_list: D036022:Capsid Proteins; C442521:VP2 protein, Chicken anemia virus