Video Experimental Relacionado

Updated: Sep 9, 2025

Repressing Gene Transcription by Redirecting Cellular Machinery with Chemical Epigenetic Modifiers

Repressing Gene Transcription by Redirecting Cellular Machinery with Chemical Epigenetic Modifiers

Published on: September 20, 2018

La represión activa coordinada opera a través de la cooperatividad del factor de transcripción y múltiples estados

Virginia L Pimmett¹, Maria Douaihy^1,2, Louise Maillard¹

¹Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS UMR 5535, Montpellier, France.

Nature communications

|September 1, 2025

Resumen

La represión activa refina la expresión génica a través de la dinámica del represor Snail (Sna). Este estudio revela la represión cooperativa mediada por potenciadores, cambiando la transcripción a un estado inactivo estable e impactando el destino celular.

Área de la Ciencia:

Biología molecular
Biología del desarrollo
La genética

Sus antecedentes:

La represión activa es crucial para regular la transcripción génica en las regiones eucromáticas.
Los mecanismos dinámicos que subyacen a la represión activa no se comprenden bien.
La dinámica del represor de caracol (Sna) proporciona un modelo para estudiar la represión en los tejidos en desarrollo.

Objetivo del estudio:

Investigar la dinámica de la represión activa mediada por Snail (Sna) en un tejido en desarrollo.
Aclarar el papel de los elementos potenciadores en la mediación de la represión.
Comprender cómo la cooperatividad de los factores de transcripción influye en las dinámicas de represión y las decisiones sobre el destino celular.

Principales métodos:

Se emplearon técnicas de imagen en vivo para observar la dinámica de la expresión génica.
El modelado matemático fue utilizado para analizar la cinética de la represión.
Se realizó un análisis mutacional de los sitios de unión de Snail (Sna) para evaluar su papel en la represión.

Principales resultados:

La represión mediada por sna es cooperativa, con la cooperatividad impulsada principalmente por un potenciador distal.
La represión altera la dinámica de ruptura de la transcripción, pasando de un sistema de dos estados (ON / OFF) a un sistema de tres estados (reprimido) con estados OFF distintos.
Las mutaciones en los sitios de unión de Sna indican que la represión establece un estado inactivo duradero, estabilizado por la cooperatividad.

Conclusiones:

La cooperación de los factores de transcripción es esencial para establecer una represión estable.
La dinámica de la represión, influenciada por la actividad del potenciador y la cooperación, juega un papel clave en la coordinación de las decisiones sobre el destino celular.
Este estudio proporciona información cuantitativa sobre los mecanismos de la represión activa y su impacto en los procesos de desarrollo.

Más Videos Relacionados

Artificial RNA Polymerase II Elongation Complexes for Dissecting Co-transcriptional RNA Processing Events

Artificial RNA Polymerase II Elongation Complexes for Dissecting Co-transcriptional RNA Processing Events

Published on: May 13, 2019

In Vitro Selection of Engineered Transcriptional Repressors for Targeted Epigenetic Silencing

In Vitro Selection of Engineered Transcriptional Repressors for Targeted Epigenetic Silencing

Published on: May 5, 2023

Videos de Conceptos Relacionados

RNA Polymerase II Accessory Proteins

RNA Polymerase II Accessory Proteins

Proteins that regulate transcription can do so either via direct contact with RNA Polymerase or through indirect interactions facilitated by adaptors, mediators, histone-modifying proteins, and nucleosome remodelers. Direct interactions to activate transcription is seen in bacteria as well as in some eukaryotic genes. In these cases, upstream activation sequences are adjacent to the promoters, and the activator proteins interact directly with the transcriptional machinery. For example, in...

Co-activators and Co-repressors

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 Inhibitors

Eukaryotic 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...

Cooperative Binding of Transcription Regulators

Cooperative Binding of Transcription Regulators

Transcriptional regulators bind to specific cis-regulatory sequences in the DNA to regulate gene transcription. These cis-regulatory sequences are very short, usually less than ten nucleotide pairs in length. The short length means that there is a high probability of the exact same sequence randomly occurring throughout the genome. Since regulators can also bind to groups of similar sequences, this further increases the chances of random binding. Transcriptional regulators form...

Prokaryotic Transcriptional Activators and Repressors

Prokaryotic Transcriptional Activators and Repressors

The organization of prokaryotic genes in their genome is notably different from that of eukaryotes. Prokaryotic genes are organized, such that the genes for proteins involved in the same biochemical process or function are located together in groups. This group of genes, along with their regulatory elements, are collectively known as an operon. The functional genes in an operon are transcribed together to give a single strand of mRNA known as polycistronic mRNA.
Transcription of prokaryotic...

Combinatorial Gene Control

Combinatorial Gene Control

Combinatorial gene control is the synergistic action of several transcriptional factors to regulate the expression of a single gene. The absence of one or more of these factors may lead to a significant difference in the level of gene expression or repression.
The expression of more than 30,000 genes is controlled by approximately 2000-3000 transcription factors. This is possible because a single transcription factor can recognize more than one regulatory sequence. The specificity in gene...