Involvement of chromatin and histone deacetylation in SV40 T antigen transcription regulation

Related Experiment Video

Updated: Jul 16, 2026

Electrophoretic Analysis of Replication Through Structure-Prone DNA Repeats Within the SV40-Based Human Episome
05:22

Electrophoretic Analysis of Replication Through Structure-Prone DNA Repeats Within the SV40-Based Human Episome

Published on: September 13, 2024

Ester Valls1, Noemí Blanco-García, Naiara Aquizu

  • 1Instituto de Biología Molecular de Barcelona, CID, Consejo Superior de Investigaciones Científicas, Parc Cientific de Barcelona, Barcelona, Spain.

Nucleic Acids Research
|March 8, 2007
PubMed

Insights

Simian Virus 40 (SV40) large T antigen represses cellular transcription by interacting with HDAC1, leading to histone deacetylation. This mechanism is crucial for oncoviral protein-mediated cellular transformation.

Area of Science:

  • Molecular biology
  • Virology
  • Epigenetics

Background:

  • Simian Virus 40 (SV40) large T antigen (T Ag) is a viral oncoprotein.
  • Its role in regulating viral and cellular transcription is known, but the mechanisms are unclear.

Purpose of the Study:

  • To elucidate the mechanisms by which SV40 T Ag regulates transcriptional activity.
  • To investigate the role of histone acetylation and deacetylation in SV40 T Ag-mediated effects.

Main Methods:

  • Investigated T Ag's effect on CBP-mediated transcription.
  • Assessed histone H3 deacetylation and its sensitivity to Trichostatin A (TSA).
  • Examined T Ag interaction with Histone Deacetylase 1 (HDAC1) in vitro.
  • Utilized small interfering RNA (siRNA) to reduce HDAC1 levels.

Main Results:

  • SV40 T Ag represses CBP-mediated transcriptional activity.
  • This repression is associated with histone H3 deacetylation and is TSA-sensitive.
  • T Ag interacts with HDAC1 independently of the retinoblastoma tumor suppressor protein (Rb).
  • Overexpression of HDAC1 enhances T Ag's antagonism of CBP transactivation and leads to TK promoter deacetylation.
  • Reducing HDAC1 levels via siRNA partially reverses T Ag-induced repression.

Conclusions:

  • SV40 T Ag utilizes HDAC1 to repress CBP-mediated transcription.
  • Histone deacetylation is a key mechanism in SV40 T Ag's function.
  • The balance of histone acetylation/deacetylation is critical in oncoviral protein-induced cellular transformation.

More Related Videos

Chromatin Immunoprecipitation (ChIP) to Assay Dynamic Histone Modification in Activated Gene Expression in Human Cells13:20

Chromatin Immunoprecipitation (ChIP) to Assay Dynamic Histone Modification in Activated Gene Expression in Human Cells

Published on: July 29, 2010

Lentiviral Vector Platform for the Efficient Delivery of Epigenome-editing Tools into Human Induced Pluripotent Stem Cell-derived Disease Models13:47

Lentiviral Vector Platform for the Efficient Delivery of Epigenome-editing Tools into Human Induced Pluripotent Stem Cell-derived Disease Models

Published on: March 29, 2019

Related Concept Videos

Chromatin Modification in iPS Cells01:32

Chromatin Modification in iPS Cells

Chromatin modification alters gene expression; therefore, scientists can add histone-modifying enzymes, histone variants, and chromatin remodeling complexes to somatic cells to aid reprogramming into pluripotent stem (iPS) cells.
Compact chromatin makes reprogramming difficult. Enzymes, such as histone demethylases and acetyltransferases, are often added during reprogramming to loosen the chromatin, making the DNA more accessible to transcription factors. Molecules that inhibit histone...
Spreading of Chromatin Modifications02:25

Spreading of Chromatin Modifications

The histone proteins in the nucleosomes are post-translationally modified (PTM) to increase or decrease access to DNA. The commonly observed PTMs are methylation, acetylation, phosphorylation, and ubiquitination of lysine amino acids in the histone H3 tail region. These histone modifications have specific meaning for the cell. Hence, they are called "histone code". The protein complex involved in histone modification is termed as "reader-writer" complex.
Writers
The writer is an enzyme that can...
Co-activators and Co-repressors02:04

Co-activators and Co-repressors

Gene transcription is regulated by the synergistic action of several proteins that form a complex at a gene regulatory site. This is observed in eukaryotes, where the regulation of gene expression is a complex process. Regulatory proteins in eukaryotes can broadly be classified into two types – regulators that bind directly to specific DNA sequences and co-regulators that associate with regulatory proteins but cannot directly bind to the DNA. These co-regulators are further divided into...
Eukaryotic Transcription Activators02:42

Eukaryotic Transcription Activators

Transcription activators are proteins that promote the transcription of genes from DNA to RNA. In most cases, these proteins contain two separate domains ‒ a domain that binds to DNA and a domain for activating transcription; however, in some cases, a single domain is responsible for both binding and activation of transcription, as seen in the glucocorticoid receptor and MyoD.
The binding domains are capable of recognizing and interacting with regulatory sequences on the DNA. These domains are...
Histone Modification02:32

Histone Modification

The histone proteins have a flexible N-terminal tail extending out from the nucleosome. These histone tails are often subjected to post-translational modifications such as acetylation, methylation, phosphorylation, and ubiquitination. Particular combinations of these modifications form “histone codes” that influence the chromatin folding and tissue-specific gene expression.
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
Histone Modification02:32

Histone Modification

The histone proteins have a flexible N-terminal tail extending out from the nucleosome. These histone tails are often subjected to post-translational modifications such as acetylation, methylation, phosphorylation, and ubiquitination. Particular combinations of these modifications form “histone codes” that influence the chromatin folding and tissue-specific gene expression.
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...