Identification of a novel basic helix-loop-helix-PAS factor, NXF, reveals a Sim2 competitive, positive regulatory role in dendritic-cytoskeleton modulator drebrin gene expression.
Mol Cell Biol
; 24(2): 608-16, 2004 Jan.
Article
en En
| MEDLINE
| ID: mdl-14701734
ABSTRACT
Sim2, a basic helix-loop-helix (bHLH)-PAS transcriptional repressor, is thought to be involved in some symptoms of Down's syndrome. In the course of searching for hypothetical Sim2 relatives, we isolated another bHLH-PAS factor, NXF. NXF was a novel gene and was selectively expressed in neuronal tissues. While no striking homolog of NXF was found in vertebrates, a Caenorhabditis elegans putative transcription factor, C15C8.2, showed similarity in the bHLH-PAS domain. NXF had an activation domain as a transcription activator, and Arnt-type bHLH-PAS subfamily members were identified as the heterodimer partners of NXF. The NXF/Arnt heterodimer was capable of binding and activating a subset of Sim2/Arnt target DNA variants, and Sim2 could compete with the NXF activity on the elements. We showed that Drebrin had several such NXF/Arnt binding elements on the promoter, which could be direct or indirect cross talking points between NXF (activation) and Sim2 (repression) action. Drebrin has been reported to be engaged in dendritic-cytoskeleton modulation at synapses, and such a novel NXF signaling system on neural gene promoter may be a molecular target of the adverse effects of Sim2 in the mental retardation of Down's syndrome.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Factores de Transcripción
/
Neuropéptidos
/
Proteínas de Unión al ADN
Tipo de estudio:
Diagnostic_studies
/
Prognostic_studies
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Mol Cell Biol
Año:
2004
Tipo del documento:
Article
País de afiliación:
Japón