Retinoblastoma-related protein pRb2/p130 and its binding to the B-myb promoter increase during human neuroblastoma differentiation.
J Cell Biochem
; 67(3): 297-303, 1997 Dec 01.
Article
en En
| MEDLINE
| ID: mdl-9361185
ABSTRACT
Neuroblastoma cells can undergo neural differentiation upon treatment with a variety of chemical inducers and growth factors. During this process, many cell cycle-related genes are downregulated while differentiation-specific genes are triggered. The retinoblastoma family proteins, pRb, p107, and pRb2/p130, are involved in transcriptional repression of proliferation genes, mainly through their interaction with the E2F transcription factors. We report that pRb2/p130 expression levels increased during differentiation of neuroblastoma cell line LAN-5. On the other hand, both pRb and p107 decreased and underwent progressive dephosphorylation at late differentiation times. The expression of B-myb and c-myb, two targets of the retinoblastoma family proteins, were downregulated in association with the increase of pRb2/p130, which was detected as the major component of the complex with E2F on the E2F site of the B-myb promoter in differentiated cells. Interestingly, E2F4, a preferential partner of p107 and pRb2/p130, was upregulated and underwent changes in cellular localization during differentiation. In conclusion, our data suggest a major role of pRb2/p130 in the regulation of B-myb promoter during neural differentiation despite the importance of cofactors in modulating the function of the retinoblastoma family proteins.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Fosfoproteínas
/
Factores de Transcripción
/
Proteínas
/
Proteínas Portadoras
/
Regiones Promotoras Genéticas
/
Proteínas de Ciclo Celular
/
Proteínas de Unión al ADN
/
Neuroblastoma
/
Neuronas
Límite:
Humans
Idioma:
En
Revista:
J Cell Biochem
Año:
1997
Tipo del documento:
Article
País de afiliación:
Italia