Luteinizing hormone receptor mRNA down-regulation is mediated through ERK-dependent induction of RNA binding protein.
Mol Endocrinol
; 25(2): 282-90, 2011 Feb.
Article
em En
| MEDLINE
| ID: mdl-21147848
ABSTRACT
The ligand-induced down-regulation of LH receptor (LHR) expression in the ovaries, at least in part, is regulated by a posttranscriptional process mediated by a specific LH receptor mRNA binding protein (LRBP). The LH-mediated signaling pathways involved in this process were examined in primary cultures of human granulosa cells. Treatment with 10 IU human chorionic gonadotropin (hCG) for 12 h resulted in the down-regulation of LHR mRNA expression while producing an increase in LHR mRNA binding to LRBP as well as a 2-fold increase in LRBP levels. The activation of ERK1/2 pathway in LH-mediated LHR mRNA down-regulation was also established by demonstrating the translocation of ERK1/2 from the cytosol to the nucleus using confocal microcopy. Inhibition of protein kinase A using H-89 or ERK1/2 by U0126 abolished the LH-induced LHR mRNA down-regulation. These treatments also abrogated both the increases in LRBP levels as well as the LHR mRNA binding activity. The abolishment of the hCG-induced increase in LRBP levels and LHR mRNA binding activity was further confirmed by transfecting granulosa cells with ERK1/2 specific small interfering RNA. This treatment also reversed the hCG-induced down-regulation of LHR mRNA. These data show that LH-regulated ERK1/2 signaling is required for the LRBP-mediated down-regulation of LHR mRNA.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Receptores do LH
/
RNA Mensageiro
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Regulação para Baixo
/
Fosfotransferases (Aceptor do Grupo Álcool)
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MAP Quinases Reguladas por Sinal Extracelular
Limite:
Female
/
Humans
Idioma:
En
Ano de publicação:
2011
Tipo de documento:
Article