Related Experiment Video
Updated: Jul 7, 2026
10:22
Isolation of Viral Replication Compartment-enriched Sub-nuclear Fractions from Adenovirus-infected Normal Human Cells
Published on: November 12, 2015
pRB-E2F1 complexes are resistant to adenovirus E1A-mediated disruption
L A Seifried1, S Talluri, M Cecchini
1Cancer Research Labs, 790 Commissioners Road East, London, Ontario, Canada.
Journal of Virology
|February 29, 2008
Summary
Adenovirus E1A protein disrupts retinoblastoma protein (pRB) interactions, but spares the E2F1 interaction. This selective disruption promotes viral transcription and cell cycle progression while E2F1 maintains cell viability.
Area of Science:
- Molecular Biology
- Virology
- Cell Cycle Regulation
Background:
- Adenovirus E1A protein disrupts pRB-E2F interactions, driving viral transcription and cell cycle progression.
- E2F1, an E2F family member, regulates proliferation, apoptosis, and DNA repair.
- A newly identified pRB interaction site specifically binds E2F1, enabling separate control of proliferation.
Purpose of the Study:
- Investigate how E1A affects pRB's control over E2F1, considering the distinct pRB-E2F1 interaction site.
- Determine the impact of E1A on the specific pRB-E2F1 interaction during adenovirus infection.
- Elucidate the role of E2F1 in maintaining cell viability in the context of E1A expression.
Main Methods:
- Utilized mutant forms of pRB to isolate E2F1 binding to specific sites.
- Analyzed pRB-E2F complexes during adenovirus infection.
- Assessed cell viability in response to E1A expression.
Main Results:
- pRB-E2F1 interactions are resistant to E1A-mediated disruption.
- E1A cannot disrupt the unique E2F1 interaction with pRB, even when binding is restricted to the specific site.
- Adenovirus infection selectively maintains pRB-E2F1 interactions in the presence of E1A.
- E2F1 actively maintains cell viability when E1A is expressed.
Conclusions:
- Adenovirus E1A achieves selective disruption of pRB-E2F interactions, promoting viral transcription and cell cycle advancement.
- The unique pRB-E2F1 interaction is resistant to E1A disruption, ensuring cell viability during infection.
- E2F1 plays a crucial role in cell survival despite E1A's oncogenic functions.
Related Concept Videos
01:23Negative 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.
02:23Abnormal 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...
01:20The 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,...
01:51Mechanisms of Retrovirus-induced Cancers
Retroviruses are RNA viruses that have been shown to cause cancers in diverse species, including chickens, mice, cats, and monkeys. The RNA genomes of these viruses are first reverse-transcribed into single and then double-stranded DNA (dsDNA) copies. This dsDNA called proviral DNA then integrates into the host genome. Subsequently, the host cell transcribes the proviral DNA in concert with the chromosomal DNA. This leads to the production of viral RNA and proteins that assemble at the host...
01:51Mechanisms of Retrovirus-induced Cancers
Retroviruses are RNA viruses that have been shown to cause cancers in diverse species, including chickens, mice, cats, and monkeys. The RNA genomes of these viruses are first reverse-transcribed into single and then double-stranded DNA (dsDNA) copies. This dsDNA called proviral DNA then integrates into the host genome. Subsequently, the host cell transcribes the proviral DNA in concert with the chromosomal DNA. This leads to the production of viral RNA and proteins that assemble at the host...
01:52Eukaryotic Transcription Inhibitors
Certain biochemical processes, such as embryonic development and cell growth regulation, depend on the repression of specific genes. DNA binding proteins known as eukaryotic transcription inhibitors regulate the repression of gene expression in eukaryotes. The presence of these inhibitors at the required location and time in the cell is triggered by the presence of hormones and additional signals from other cells.
Eukaryotic transcription inhibitors usually contain two distinct domains, a DNA...
Eukaryotic transcription inhibitors usually contain two distinct domains, a DNA...