English   español  
Por favor, use este identificador para citar o enlazar a este item: http://hdl.handle.net/10261/8246
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:

Identification of a non-canonical E-box motif as a regulatory element in the proximal promoter region of the apolipoprotein E gene

AutorSalero, Enrique; Giménez Martín, Cecilio ; Zafra, Francisco
Palabras claveAlzheimer's disease
Apolipoprotein E
Gene regulation
Nervous system
Upstream regulatory factor (USF).
Fecha de publicación25-nov-2002
EditorBiochemical Society
CitaciónBiochem. J. (2003) 370 (979–986)
ResumenWe have used the yeast one-hybrid system to identify transcription factors with binding capability to specific sequences in proximal regions of the apolipoprotein E gene (APOE) promoter. The sequence between -113 and -80nt, which contains regulatory elements in various cell types, was used as a bait to screen a human brain cDNA library. Four cDNA clones that encoded portions of the human upstream-stimulatory-factor (USF) transcription factor were isolated. Electrophoretic-mobility-shift assays ('EMSAs') using nuclear extracts from various human cell lines as well as from rat brain and liver revealed the formation of two DNA–protein complexes within the sequence CACCTCGTGAC (region -101/-91 of the APOE promoter) that show similarity to the E- box element. The retarded complexes contained USF1, as deduced from competition and supershift assays. Functional experiments using different APOE promoter–luciferase reporter constructs transiently transfected into U87, HepG2 or HeLa cell lines showed that mutations that precluded the formation of complexes decreased the basal activity of the promoter by about 50%. Overexpression of USF1 in U87 glioblastoma cells led to an increased activity of the promoter that was partially mediated by the atypical E-box. The stimulatory effect of USF1 was cell-type specific, as it was not observed in hepatoma HepG2 cells. Similarly, overexpression of a USF1 dominant-negative mutant decreased the basal activity of the promoter in glioblastoma, but not in hepatoma, cells. These data indicated that USF, and probably other related transcription factors, might be involved in the basal transcriptional machinery of APOE by binding to a non-canonical E-box motif within the proximal promoter
Versión del editorhttp://dx.doi.org/10.1042/BJ20021142
Aparece en las colecciones: (CBM) Artículos
Ficheros en este ítem:
Fichero Descripción Tamaño Formato  
ESalero_BiochemJ_979.pdf251,94 kBAdobe PDFVista previa
Mostrar el registro completo

Artículos relacionados:

NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.