Video Experimental Relacionado
Updated: Jul 26, 2026

12:19
Analysis of Cell Cycle Position in Mammalian Cells
Published on: January 21, 2012
La proteína del retinoblastoma cambia el sitio E2F del elemento positivo al negativo
S J Weintraub1, C A Prater, D C Dean
1Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110.
Nature
|July 16, 1992
Resumen
El complejo de la proteína del retinoblastoma (Rb) -E2F silencia activamente la transcripción génica al unirse a los sitios E2F. Esta unión es dependiente de Rbb.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- Regulación del ciclo celular Reglamento del ciclo celular.
- Transcripción genética de la transcripción de genes.
Sus antecedentes:
- Los sitios E2F son elementos promotores cruciales para los genes tempranos del adenovirus y la progresión del ciclo celular.
- La proteína E2F forma un complejo con la proteína del ciclo celular Rb, que anteriormente se pensaba que inactivaba E2F.
Objetivo del estudio:
- Investigar el papel funcional del complejo Rb-E2F en la transcripción génica.
- Para aclarar el mecanismo por el cual Rb influye en la actividad E2F durante el ciclo celular.
Principales métodos:
- Análisis de la actividad del complejo Rb-E2F en los sitios promotores de E2F.
- Investigación de la función del sitio E2F en la presencia y ausencia de Rb. activo.
- Correlación del estado de fosforilación de Rb con la actividad de unión y transcripción de E2F.
Principales resultados:
- El complejo Rb-E2F es transcripcionalmente activo e inhibe la expresión génica cuando se une a los sitios E2F.
- E2F actúa como un elemento transcripcional positivo en ausencia de Rb. activo.
- La unión de Rb-E2F depende de la fosforilación de Rb, que varía durante el ciclo celular.
Conclusiones:
- El complejo Rb-E2F juega un papel integral en el silenciamiento de genes a través de la inhibición de la transcripción.
- El sitio E2F funciona dinámicamente como un elemento regulador positivo o negativo basado en la fosforilación de Rb.
- Esta regulación cíclica de los sitios E2F por Rb puede controlar la activación e inhibición de genes a lo largo del ciclo celular.
Videos de Conceptos Relacionados
Negative Regulator Molecules
Positive regulators allow a cell to advance through cell cycle checkpoints. Negative regulators have an equally important role as they terminate a cell’s progression through the cell cycle—or pause it—until the cell meets specific criteria.
Abnormal Proliferation
Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the daughter...
The Ras Gene
The Ras-gene-encoded proteins are regulators of signaling pathways controlling cell proliferation, differentiation, or cell survival. The Ras-gene family in humans constitutes three primary members—the HRas, NRas, and KRas. These genes code for four functionally distinct yet closely related proteins—the HRas, NRas, KRas4A, and KRas4B. The involvement of mutant Ras genes in human cancer was first discovered in 1982 and is among the most common causes of human tumorigenesis.
Ras is a superfamily...
Ras is a superfamily...
mTOR Signaling and Cancer Progression
The mammalian target of rapamycin or mTOR protein was discovered in 1994 due to its direct interaction with rapamycin. The protein gets its name from a yeast homolog called TOR. The mTOR protein complex in mammalian cells plays a major role in balancing anabolic processes such as the synthesis of proteins, lipids, and nucleotides and catabolic processes, such as autophagy in response to environmental cues, such as availability of nutrients and growth factors.
The mTOR pathway or the...
The mTOR pathway or the...
The Retinoblastoma Gene
Tumor suppressor genes are normal genes that can slow down cell division, repair DNA mistakes, or program the cells for apoptosis in case of irreparable damage. Hence, they play an essential role in preventing the proliferation of damaged cells.
The first-ever tumor suppressor gene called Rb was identified in retinoblastoma - a rare eye tumor in children. In inherited forms of the disease, a child inherits one defective copy of the Rb gene, which predisposes them to retinoblastoma. However,...
The first-ever tumor suppressor gene called Rb was identified in retinoblastoma - a rare eye tumor in children. In inherited forms of the disease, a child inherits one defective copy of the Rb gene, which predisposes them to retinoblastoma. However,...
The Retinoblastoma Gene
Tumor suppressor genes are normal genes that can slow down cell division, repair DNA mistakes, or program the cells for apoptosis in case of irreparable damage. Hence, they play an essential role in preventing the proliferation of damaged cells.
The first-ever tumor suppressor gene called Rb was identified in retinoblastoma - a rare eye tumor in children. In inherited forms of the disease, a child inherits one defective copy of the Rb gene, which predisposes them to retinoblastoma. However,...
The first-ever tumor suppressor gene called Rb was identified in retinoblastoma - a rare eye tumor in children. In inherited forms of the disease, a child inherits one defective copy of the Rb gene, which predisposes them to retinoblastoma. However,...

