Identification of a putative nuclear export signal motif in human NANOG homeobox domain.
Biochem Biophys Res Commun
; 421(3): 484-9, 2012 May 11.
Article
em En
| MEDLINE
| ID: mdl-22516749
ABSTRACT
NANOG is a homeobox-containing transcription factor that plays an important role in pluripotent stem cells and tumorigenic cells. To understand how nuclear localization of human NANOG is regulated, the NANOG sequence was examined and a leucine-rich nuclear export signal (NES) motif ((125)MQELSNILNL(134)) was found in the homeodomain (HD). To functionally validate the putative NES motif, deletion and site-directed mutants were fused to an EGFP expression vector and transfected into COS-7 cells, and the localization of the proteins was examined. While hNANOG HD exclusively localized to the nucleus, a mutant with both NLSs deleted and only the putative NES motif contained (hNANOG HD-ΔNLSs) was predominantly cytoplasmic, as observed by nucleo/cytoplasmic fractionation and Western blot analysis as well as confocal microscopy. Furthermore, site-directed mutagenesis of the putative NES motif in a partial hNANOG HD only containing either one of the two NLS motifs led to localization in the nucleus, suggesting that the NES motif may play a functional role in nuclear export. Furthermore, CRM1-specific nuclear export inhibitor LMB blocked the hNANOG potent NES-mediated export, suggesting that the leucine-rich motif may function in CRM1-mediated nuclear export of hNANOG. Collectively, a NES motif is present in the hNANOG HD and may be functionally involved in CRM1-mediated nuclear export pathway.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Receptores Citoplasmáticos e Nucleares
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Proteínas de Homeodomínio
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Carioferinas
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Sinais de Exportação Nuclear
Tipo de estudo:
Diagnostic_studies
/
Prognostic_studies
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Biochem Biophys Res Commun
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Coréia do Sul