The Tpl-2 protooncoprotein activates the nuclear factor of activated T cells and induces interleukin 2 expression in T cell lines.
Proc Natl Acad Sci U S A
; 95(7): 3827-32, 1998 Mar 31.
Article
en En
| MEDLINE
| ID: mdl-9520452
ABSTRACT
Tpl-2 expression is induced within 30-60 min after ConA stimulation of rat splenocytes, suggesting that it may contribute to the induction of IL-2 during T cell activation. Herein we show that wild-type and carboxyl-terminally truncated (activated) Tpl-2 activate the nuclear factor of activated T cells (NFAT) and induce interleukin 2 (IL-2) expression in EL4 cells. In Jurkat cells the truncated Tpl-2 activates NFAT and induces IL-2, whereas wild-type Tpl-2 activates NFAT only when cotransfected with NFAT expression constructs, suggesting that Tpl-2 may induce NFAT activation signals. Experiments in NIH 3T3 cells revealed that the NFATp isoform, but not the NFATc or NFATx isoform, undergoes nuclear translocation when coexpressed with wild-type Tpl-2 and confirmed this hypothesis. Activation of NFAT by anti-CD3 stimulation but not by phorbol 12-myristate 13-acetate and ionomycin in Jurkat cells was inhibited by the kinase-dead Tpl-2K167M, suggesting that Tpl-2 contributes to the transduction of NFAT activation signals originating in the T cell receptor. The Tpl-2-mediated induction of IL-2 was not observed in T cell lymphoma lines other than EL4 and Jurkat, as well as in normal T cells. NFAT activation by Tpl-2, however, was observed in several cell lines including some of nonhematopoietic origin. The activation of NFAT by Tpl-2 in different cell types defines a molecular mechanism that may contribute to its oncogenic potential.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Activación de Linfocitos
/
Linfocitos T
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Regulación de la Expresión Génica
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Proteínas Proto-Oncogénicas
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Interleucina-2
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Proteínas Serina-Treonina Quinasas
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Quinasas Quinasa Quinasa PAM
Límite:
Animals
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Humans
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Año:
1998
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
EEUU
/
ESTADOS UNIDOS
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ESTADOS UNIDOS DA AMERICA
/
EUA
/
UNITED STATES
/
UNITED STATES OF AMERICA
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US
/
USA