beta-catenin can be transported into the nucleus in a Ran-unassisted manner.
Mol Biol Cell
; 10(4): 1119-31, 1999 Apr.
Article
en En
| MEDLINE
| ID: mdl-10198061
ABSTRACT
The nuclear accumulation of beta-catenin plays an important role in the Wingless/Wnt signaling pathway. This study describes an examination of the nuclear import of beta-catenin in living mammalian cells and in vitro semi-intact cells. When injected into the cell cytoplasm, beta-catenin rapidly migrated into the nucleus in a temperature-dependent and wheat germ agglutinin-sensitive manner. In the cell-free import assay, beta-catenin rapidly migrates into the nucleus without the exogenous addition of cytosol, Ran, or ATP/GTP. Cytoplasmic injection of mutant Ran defective in its GTP hydrolysis did not prevent beta-catenin import. Studies using tsBN2, a temperature-sensitive mutant cell line that possesses a point mutation in the RCC1 gene, showed that the import of beta-catenin is insensitive to nuclear Ran-GTP depletion. These results show that beta-catenin possesses the ability to constitutively translocate through the nuclear pores in a manner similar to importin beta in a Ran-unassisted manner. We further showed that beta-catenin also rapidly exits the nucleus in homokaryons, suggesting that the regulation of nuclear levels of beta-catenin involves both nuclear import and export of this molecule.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Proteínas Nucleares
/
Transactivadores
/
Núcleo Celular
/
Receptores Citoplasmáticos y Nucleares
/
Proteínas de Unión al GTP
/
Proteínas del Citoesqueleto
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Mol Biol Cell
Asunto de la revista:
BIOLOGIA MOLECULAR
Año:
1999
Tipo del documento:
Article
País de afiliación:
Japón