Video Experimental Relacionado
Updated: Jul 13, 2026
09:14
Examination of Proteins Bound to Nascent DNA in Mammalian Cells Using BrdU-ChIP-Slot-Western Technique
Published on: January 14, 2016
Un papel para la histona H2A de Saccharomyces cerevisiae en la reparación del ADN
J A Downs1, N F Lowndes, S P Jackson
1The Wellcome Trust and Cancer Research Campaign, Institute of Cancer and Developmental Biology, and Department of Zoology, University of Cambridge, UK.
Nature
|January 5, 2001
Resumen
La fosforilación de la histona H2A por Mec1 es crucial para la reparación de la ruptura de la doble hebra del ADN y la estructura de la cromatina. Esta modificación mejora la supervivencia al facilitar las vías de reparación de unión de extremos no homólogos.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- Genética La genética.
- Biología celular Biología celular.
Sus antecedentes:
- Las proteínas histonas compactan el ADN en nucleosomas, formando cromatina, esencial para los procesos nucleares.
- La regulación de la estructura de la cromatina es vital para la replicación y transcripción del ADN.
- Las vías de respuesta al daño del ADN pueden interactuar con la modulación de la estructura de la cromatina.
Objetivo del estudio:
- Para caracterizar un motivo conservado en la histona H2A de Saccharomyces cerevisiae.
- Para investigar el papel de la fosforilación de este motivo en la reparación de la ruptura de doble hebra del ADN.
- Para determinar la influencia del motivo en la estructura de la cromatina y la supervivencia celular.
Principales métodos:
- Caracterización de un motivo conservado en la histona H2A.
- Análisis de los sitios de fosforilación para las fosfatidilinositol-3-OH quinasa kinasas relacionadas (PIKKs).
- Evaluación de las tasas de supervivencia en respuesta a los agentes que dañan el ADN.
- Investigar los mecanismos de reparación del ADN, específicamente la unión de extremos no homólogos.
- Evaluación de los efectos sobre la estructura de la cromatina de orden superior.
Principales resultados:
- Se identificó un motivo conservado con un sitio de fosforilación PIKK en la histona H2A.
- La fosforilación de este motivo por Mec1 es inducida por el daño del ADN.
- El motivo es esencial para la supervivencia después de las rupturas de doble cadena de ADN.
- Se requiere para la reparación eficiente de uniones finales no homólogas.
- El motivo influye en la estructura de la cromatina de orden superior.
Conclusiones:
- La fosforilación de la histona H2A por Mec1 juega un papel crítico en la reparación de la ruptura de la doble hebra del ADN.
- Esta modificación afecta la estructura de la cromatina, lo que facilita la reparación eficiente del ADN.
- El motivo identificado es un componente clave en la vía de respuesta al daño del ADN.
Videos de Conceptos Relacionados
02:32Histone 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,...
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
02:25Spreading 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...
Writers
The writer is an enzyme that can...
02:04Fixing Double-strand Breaks
The double-stranded structure of DNA has two major advantages. First, it serves as a safe repository of genetic information where one strand serves as the back-up in case the other strand is damaged. Second, the double-helical structure can be wrapped around proteins called histones to form nucleosomes, which can then be tightly wound to form chromosomes. This way, DNA chains up to 2 inches long can be contained within microscopic structures in a cell. A double-stranded break not only damages...
02:36DNA Damage can Stall the Cell Cycle
In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...
02:32Histone 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,...
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
02:36DNA Damage Can Stall the Cell Cycle
In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...