Regulation of Inhibitors of Differentiation Family Proteins by Thyroid-Stimulating Hormone in FRTL-5 Thyroid Cells
Journal of Korean Medical Science
;
: 262-269, 2008.
Artículo
en Inglés
| WPRIM
| ID: wpr-113708
ABSTRACT
Members of the inhibitors of differentiation (Id) family of helix-loop-helix (HLH) proteins are known to play important roles in the proliferation and differentiation of many cell types. Thyroid-stimulating hormone (TSH) regulates proliferation and differentiation by activating TSH receptor (TSHR) in thyrocytes. In this study, we found that Id2, one of the Id family proteins, is a major target for regulation by TSH in FRTL-5 thyroid cells. TSH rapidly increases the Id2 mRNA level in FRTL-5 thyroid cells but the Id2 protein showed biphasic regulatory patterns, being transiently reduced and subsequently induced by TSH treatment. Transient reduction of Id2 protein was noted within 2 hr of TSH treatment and was mediated by proteasomal degradation. Moreover, reduced Id2 expression correlated with the activity of the phosphatidylinositol 3 kinase pathway, which is activated by TSH. Although TSH increases the activity of the Id2 promoter, TSH-induced activation of this promoter was independent of c-Myc. Id2 did not alter TTF-1- and Pax-8-mediated effects on the regulation of the Tg promoter. Thus, in summary, we found that TSH regulates Id2 expression, but that Id2 does not alter the expression of thyroid-specific genes, such as Tg, in FRTL-5 thyroid cells.
Texto completo:
Disponible
Índice:
WPRIM (Pacífico Occidental)
Asunto principal:
Tiroglobulina
/
Glándula Tiroides
/
Tirotropina
/
Diferenciación Celular
/
Regulación de la Expresión Génica
/
Proteínas Proto-Oncogénicas c-myc
/
Regiones Promotoras Genéticas
/
Proliferación Celular
/
Factores de Transcripción Paired Box
/
Proteína 2 Inhibidora de la Diferenciación
Límite:
Animales
Idioma:
Inglés
Revista:
Journal of Korean Medical Science
Año:
2008
Tipo del documento:
Artículo
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