Differential binding of poly(ADP-Ribose) polymerase-1 and JunD/Fra2 accounts for RANKL-induced Tcirg1 gene expression during osteoclastogenesis.
J Bone Miner Res
; 22(7): 975-83, 2007 Jul.
Article
en En
| MEDLINE
| ID: mdl-17419679
ABSTRACT
UNLABELLED We studied Tcirg1 gene expression on RANKL-induced osteoclastic differentiation of the mouse model RAW264.7 cells. We identified a mechanism involving PARP-1 inhibition release and JunD/Fra-2 binding, which is responsible for Tcirg1 gene upregulation. INTRODUCTION:
The Tcirg1 gene encodes the a3 isoform of the V-ATPase a subunit, which plays a critical role in the resorption activity of the osteoclast. Using serial deletion constructs of the Tcirg1 gene promoter, we performed a transcriptional study to identify factor(s) involved in the regulation of the RANKL-induced gene expression. MATERIALS ANDMETHODS:
The promoter activity of serial-deletion fragments of the Tcirg1 gene promoter was monitored throughout the RAW264.7 cells differentiation process. We next performed sequence analysis, EMSA, UV cross-linking, qPCR, and gel supershift experiments to identify the factor(s) interacting with the promoter.RESULTS:
A deletion of the -1297-1244 region led to the disappearance of the RANKL-induced promoter activity. EMSA experiments showed the binding of two factors that undergo differential binding on RANKL treatment. Supershift experiments led us to identify the dimer JunD/Fra-2 as the binding activity associated with the -1297/-1268 Tcirg1 gene promoter sequence in response to RANKL. Moreover, we observed poly(ADP-ribose) polymerase-1 (PARP-1) binding to an adjacent site (-1270/-1256), and this interaction was disrupted after RANKL treatment.CONCLUSIONS:
We provide data that identify junD proto-oncogene (JunD) and Fos-related antigen 2 (Fra-2) as the activator protein-1 (AP-1) factors responsible for the RANKL-induced upregulation of the mouse Tcirg1 gene expression. Moreover, we identified another binding site for PARP-1 that might account for the repression of Tcirg1 gene expression in pre-osteoclastic cells.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Osteoclastos
/
Diferenciación Celular
/
Proteínas Proto-Oncogénicas c-jun
/
Poli(ADP-Ribosa) Polimerasas
/
ATPasas de Translocación de Protón Vacuolares
/
Antígeno 2 Relacionado con Fos
/
Ligando RANK
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Revista:
J Bone Miner Res
Asunto de la revista:
METABOLISMO
/
ORTOPEDIA
Año:
2007
Tipo del documento:
Article
País de afiliación:
Francia