Differences in the ability of human T-cell lymphotropic virus type 1 (HTLV-1) and HTLV-2 tax to inhibit p53 function.
J Virol
; 74(15): 6866-74, 2000 Aug.
Article
en En
| MEDLINE
| ID: mdl-10888626
ABSTRACT
We have analyzed the functional activity of the p53 tumor suppressor in human T-cell lymphotropic virus type 2 (HTLV-2)-transformed cells. Abundant levels of the p53 protein were detected in both HTLV-2A and -2B virus-infected cell lines. The p53 was functionally inactive, however, both in transient-transfection assays using a p53 reporter plasmid and in induction of p53-responsive genes in response to gamma irradiation. We further investigated HTLV-2A Tax and HTLV-2B Tax effects on p53 activity. Interestingly, although Tax-2A and -2B inactivate p53, the Tax-2A protein appears to inhibit p53 function less efficiently than either Tax-1 or Tax-2B. In transient-cotransfection assays, Tax-1 and Tax-2B inactivated p53 by 80%, while Tax2A reduced p53 activity by 20%. In addition, Tax-2A does not increase the steady-state level of cellular p53 as well as Tax-1 or -2B does in the same assays. Cotransfection assays demonstrated that Tax-2A could efficiently transactivate CREB-responsive promoters to the same level as Tax-1 and Tax-2B, indicating that the protein was functional. This report provides evidence of the first functional difference between the HTLV-2A and -2B subtypes. This comparison of the action of HTLV-1 and HTLV-2 Tax proteins on p53 function will provide important insights into the mechanism of HTLV transformation.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Virus Linfotrópico T Tipo 1 Humano
/
Virus Linfotrópico T Tipo 2 Humano
/
Transformación Celular Viral
/
Productos del Gen tax
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Proteína p53 Supresora de Tumor
Límite:
Humans
Idioma:
En
Revista:
J Virol
Año:
2000
Tipo del documento:
Article
País de afiliación:
Estados Unidos