NF-kappaB p52, RelB and c-Rel are transported into the nucleus via a subset of importin alpha molecules.
Cell Signal
; 20(8): 1442-51, 2008 Aug.
Article
em En
| MEDLINE
| ID: mdl-18462924
ABSTRACT
In resting cells NF-kappaB transcription factors are retained in the cytoplasm as latent inactive complexes, until they are activated and rapidly transported into the nucleus. We show that all NF-kappaB proteins are imported into the nucleus via a subset of importin alpha isoforms. Our data indicate that the NF-kappaB components of the classical and alternative pathways have somewhat different specifities to importin alpha molecules. Based on the results from binding experiments of in vitro-translated and Sendai virus infection-induced or TNF-alpha-stimulated endogenous NF-kappaB proteins, it can be predicted that the specifity of NF-kappaB proteins to importin alpha molecules is different and changes upon the composition of the imported dimer. p52 protein binds directly to importin alpha3, alpha4, alpha5 and alpha6 and c-Rel binds to importin alpha5, alpha6 and alpha7 via a previously described monopartite nuclear localization signals (NLSs). Here we show that RelB, instead, has a bipartite arginine/lysine-rich NLS that mediates the binding of RelB to importin alpha5 and alpha6 and subsequent nuclear translocation of the protein. Moreover, we show that the nuclear import of p52/RelB heterodimers is mediated exclusively by the NLS of RelB. In addition, we found that the NLS of p52 mediates the nuclear import of p52/p65 heterodimers.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Núcleo Celular
/
Proteínas Proto-Oncogênicas c-rel
/
Alfa Carioferinas
/
Subunidade p52 de NF-kappa B
/
Fator de Transcrição RelB
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Revista:
Cell Signal
Ano de publicação:
2008
Tipo de documento:
Article
País de afiliação:
Finlândia