A nucleotide deletion causing a translational stop in the protease reading frame of bovine leukaemia virus (BLV) results in modified protein expression and loss of infectivity.
J Vet Med B Infect Dis Vet Public Health
; 47(5): 361-71, 2000 Jun.
Article
en En
| MEDLINE
| ID: mdl-10900827
ABSTRACT
Bovine leukaemia virus (BLV) is an oncogenic retrovirus that causes B-cell lymphocytosis and in the terminal stage of the disease lymphosarcoma. The comparison of the previously published BLV provirus sequence from Belgium, Australia and Japan showed that the protease gene (prt) of the Australian and the Japanese isolate contain a nucleotide deletion when compared to the Belgian isolate. Because all these proviruses were isolated from tumour tissue, the prt gene of functionally active and infectious proviruses from peripheral blood leucocytes (PBLs) of BLV-infected cattle and from BLV-infected fetal lamb kidney cells were sequenced. The only variations between these sequences and the Belgian isolate consist of nucleotide substitutions. The delection of one nucleotide of the prt gene of the Japanese and the Australian BLV tumour isolate caused a changed reading frame and a premature translational stop. It was shown that the Japanese provirus is non-infectious in transfected cell culture and in injected sheep. To analyse the impact of the prt mutation on viral protein expression and infectivity, the prt region of the Japanese provirus was exchanged with the prt region from the Belgian provirus. The resulting pBLVprtbelg was infectious in transfected cells and enabled the expression of gag and gag-precursor proteins. One sheep was injected with this mutated provirus and became positive in BLV-PCR, but no seroconversion was developed. The prt mutation of the Japanese tumour isolates was shown to be responsible for the loss of infectivity and changed viral expression. These results and the occurrence of this mutation in only two isolates from lymphosarcoma indicate a possible relation between the prt mutation and the induction of cell transformation.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Proteínas Virales
/
Regulación Viral de la Expresión Génica
/
Leucosis Bovina Enzoótica
/
Eliminación de Gen
/
Virus de la Leucemia Bovina
Límite:
Animals
Idioma:
En
Revista:
J Vet Med B Infect Dis Vet Public Health
Asunto de la revista:
MEDICINA VETERINARIA
/
SAUDE PUBLICA
Año:
2000
Tipo del documento:
Article
País de afiliación:
Alemania