The triiodothyronine nuclear receptor c-ErbAalpha1 inhibits avian MyoD transcriptional activity in myoblasts.
FEBS Lett
; 508(2): 236-40, 2001 Nov 16.
Article
em En
| MEDLINE
| ID: mdl-11718722
ABSTRACT
Thyroid hormone stimulates myoblast differentiation, through an inhibition of AP-1 activity occurring at the onset of differentiation. In this study we found that the T3 nuclear receptor c-ErbAalpha1 (T3Ralpha1) is involved in a mechanism preserving the duration of myoblast proliferation. Independently of the hormone presence, T3Ralpha1 represses avian MyoD transcriptional activity. Using several mutants of T3Ralpha1, we found that the hinge region plays a crucial role in the inhibition of MyoD activity. In particular, mutations of two small basic sequences included in alpha helices abrogate the T3Ralpha1/MyoD functional interaction. Similarly, the T3 receptor also represses myogenin transcriptional activity. Therefore, despite stimulating avian myoblast differentiation by a T3-dependent pathway not involving myogenic factors, T3Ralpha1 contributes to maintain an optimal myoblast proliferation period by inhibiting MyoD and myogenin activity.
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Base de dados:
MEDLINE
Assunto principal:
Codorniz
/
Transcrição Gênica
/
Tri-Iodotironina
/
Receptores dos Hormônios Tireóideos
/
Proteína MyoD
Limite:
Animals
Idioma:
En
Ano de publicação:
2001
Tipo de documento:
Article