Silencing of Fshr occurs through a conserved, hypersensitive site in the first intron.
Mol Endocrinol
; 19(8): 2112-31, 2005 Aug.
Article
en En
| MEDLINE
| ID: mdl-15817654
Expression of the FSH receptor (Fshr) is restricted to testicular Sertoli cells and ovarian granulosa cells, thereby limiting the direct targets of FSH action to these somatic cells of the gonads. Earlier studies indicate that transcription of Fshr in the gonads requires elements outside the gene's immediate 5' flanking sequence. To help uncover candidate regulatory sequences, comparative genomics and deoxyribonuclease I hypersensitivity mapping were employed. A total of 156 evolutionarily conserved sequences were found, and partial deoxyribonuclease I hypersensitivity mapping across 45 kb of 5' flanking sequence and the first intron identified four hypersensitive sites, DHS1-4. Notably, DHS1 and DHS2 localized to conserved sites in the promoter region and exon 1 and correlated with the active state of the gene. DHS3 also corresponded to a conserved site (site 7) but was more pronounced in nonexpressing myoid cells, suggesting a role in gene silencing. Transient transfection analysis of DHS3 confirmed its role in gene silencing, a function that was promoter, cell type, and position dependent. Protein-DNA binding studies on DHS3 revealed that octamer transcription factor 1 (OCT-1) and GATA-4 bound site 7, in vitro, and transient transfection analysis showed that their binding sites were required for silencing activity. Furthermore, chromatin immunoprecipitation revealed that OCT-1 bound to site 7 in the endogenous gene, but only in myoid cells. In contrast, GATA-1 bound site 7 predominantly in Sertoli cells, suggesting that it attenuates silencer activity. The findings reveal that OCT-1 binds within DHS3 to silence Fshr transcription and implicate members of the GATA family in the modulation of this activity.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Receptores de HFE
/
Regulación de la Expresión Génica
/
Silenciador del Gen
Tipo de estudio:
Prognostic_studies
Límite:
Animals
/
Humans
/
Male
Idioma:
En
Revista:
Mol Endocrinol
Asunto de la revista:
BIOLOGIA MOLECULAR
/
ENDOCRINOLOGIA
Año:
2005
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Estados Unidos