Identification of functional nuclear export sequences in human sphingosine kinase 1.
Biochem Biophys Res Commun
; 311(1): 168-73, 2003 Nov 07.
Article
en En
| MEDLINE
| ID: mdl-14575709
ABSTRACT
Sphingosine kinase (SPHK) is an enzyme that phosphorylates sphingosine to form sphingosine 1-phosphate (S1P). Human SPHK1 (hSPHK1) was localized predominantly in the cytoplasm when transiently expressed in Cos7 cells. In this study, we have found two functional nuclear export signal (NES) sequences in the middle region of hSPHK1. Deletion and mutagenesis studies revealed that the cytoplasmic localization of SPHK1 depends on its nuclear export, directed by the NES. Furthermore, upon treatment with leptomycin B, a specific inhibitor of the nuclear export receptor CRM1, a marked nuclear accumulation of hSPHK1 was observed, indicating that hSPHK1 shuttles between the cytoplasm and the nucleus. Our results provide the first evidence of the active nuclear export of SPHK1 and suggest it is mediated by a CRM1-dependent pathway.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Núcleo Celular
/
Fosfotransferasas (Aceptor de Grupo Alcohol)
/
Análisis de Secuencia de Proteína
/
Citoplasma
Tipo de estudio:
Diagnostic_studies
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Biochem Biophys Res Commun
Año:
2003
Tipo del documento:
Article
País de afiliación:
Japón