cAMP-activated Nr4a1 expression requires ERK activity and is modulated by MAPK phosphatase-1 in MA-10 Leydig cells
In Leydig cells, LH and cAMP promote ERK1/2 activation and MAPK phosphatase-1 (MKP-1) induction. MKP-1 up-regulation, which involves post-translational modifications such as ERK1/2-mediated phosphorylation, reduces ERK1/2 phosphorylation as well as Steroidogenic Acute Regulatory (StAR) protein expre...
| Autores: | , , , , |
|---|---|
| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2015 |
| País: | Argentina |
| Institución: | Consejo Nacional de Investigaciones Científicas y Técnicas |
| Repositorio: | CONICET Digital (CONICET) |
| Idioma: | inglés |
| OAI Identifier: | oai:ri.conicet.gov.ar:11336/15258 |
| Acceso en línea: | http://hdl.handle.net/11336/15258 |
| Access Level: | acceso abierto |
| Palabra clave: | Map Kinase Phosphatase Mkp-1 Erk1/2 Nr4a1 Nur77 Leydig Cells https://purl.org/becyt/ford/1.6 https://purl.org/becyt/ford/1 |
| Sumario: | In Leydig cells, LH and cAMP promote ERK1/2 activation and MAPK phosphatase-1 (MKP-1) induction. MKP-1 up-regulation, which involves post-translational modifications such as ERK1/2-mediated phosphorylation, reduces ERK1/2 phosphorylation as well as Steroidogenic Acute Regulatory (StAR) protein expression and steroidogenesis. As LH- and cAMP-promoted StAR transcription requires the induction of Nur77, product of Nr4a1 gene, we analyzed the roles of ERK1/2 and MKP-1 in 8Br–cAMP-mediated Nr4a1 expression in MA-10 Leydig cells. Pharmacological blockade of ERK1/2 activation partially reduced the 8Br–cAMP-mediated increase in both Nr4a1 messenger levels and promoter activity. MKP-1 knock-down increased 8Br–cAMP-induced promoter activity, while its over-expression produced the opposite effect. It is concluded that Nr4a1 induction is dependent on ERK1/2 and that MKP-1 negatively regulates this induction. Experiments based on the over-expression of MKP-1 mutated forms revealed that MKP-1 half life is determined by post-translational modifications in ERK-consensus sites, a regulation that modulates the effect of MKP-1 on Nr4a1 expression. |
|---|