Video Experimental Relacionado
Updated: May 28, 2026
07:42
Rapid Analysis of Circadian Phenotypes in Arabidopsis Protoplasts Transfected with a Luminescent Clock Reporter
Published on: September 17, 2016
La histona lisina desmetilasa JARID1a activa CLOCK-BMAL1 e influye en el reloj circadiano
Luciano DiTacchio1, Hiep D Le, Christopher Vollmers
1Regulatory Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA.
Science (New York, N.Y.)
|October 1, 2011
Resumen
La histona demetilasa JARID1a mejora los ritmos circadianos al aumentar la acetilación de histonas y la expresión génica. Esta proteína juega un papel crucial y no redundante en el reloj molecular central de los animales.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- Cronobiología cronobiología.
- La epigenética es la epigenética.
Sus antecedentes:
- Los ritmos circadianos están regulados por circuitos de retroalimentación de transcripción-traducción que incluyen CLOCK y BMAL1.
- Las modificaciones de la histona juegan un papel en la regulación de la expresión génica circadiana.
Objetivo del estudio:
- Para investigar el papel de JumonjiC (JmjC) y el dominio ARID que contiene histona lisina desmetilasa 1a (JARID1a) en el oscilador circadiano de mamíferos.
- Determinar el mecanismo por el cual JARID1a influye en la transcripción de genes circadianos.
Principales métodos:
- Co-inmunoprecipitación para identificar complejos de proteínas.
- Inmunoprecipitación de la cromatina para evaluar el reclutamiento de promotores y la acetilación de histonas.
- La interferencia del ARN para agotar JARID1a en las células de mamíferos.
- Análisis de la expresión génica circadiana y el período del ritmo.
- Se utilizaron modelos de Drosophila melanogaster para estudiar el homólogo de JARID1a.
Principales resultados:
- JARID1a forma un complejo con CLOCK-BMAL1 y es reclutado para el promotor Per2.
- JARID1a mejora la transcripción mediada por CLOCK-BMAL1 de manera independiente de la desmetilasa, en parte mediante la inhibición de la histona desacetilasa 1.
- El agotamiento de JARID1a reduce la acetilación de histonas en el promotor Per, amortigua la expresión génica circadiana y acorta el período circadiano.
- La expresión reducida del 'tapa' homólogo de Drosophila también altera los ritmos circadianos.
Conclusiones:
- JARID1a juega un papel no redundante en el oscilador circadiano de los mamíferos.
- La función de JARID1a en los ritmos circadianos está vinculada a la regulación epigenética de la expresión génica.
- El mecanismo de JARID1a implica la interacción con la maquinaria del reloj central y la modulación de la acetilación de histonas.
Videos de Conceptos Relacionados
02:19Circadian Rhythms and Gene Regulation
The biological clock is involved in many aspects of regulating complex physiology in all animals. It was in 1935 when German zoologists, Hans Kalmus and Erwin Bünning, discovered the existence of circadian rhythm in Drosophila melanogaster. However, the internal molecular mechanisms behind the circadian clock remained a mystery until 1984, when Jeffrey C. Hall, Michael Rosbash, and Michael W. Young discovered the expression of the Per gene oscillating over a 24-hour cycle. In subsequent years,...
02:19Circadian Rhythms and Gene Regulation
The biological clock is involved in many aspects of regulating complex physiology in all animals. It was in 1935 when German zoologists, Hans Kalmus and Erwin Bünning, discovered the existence of circadian rhythm in Drosophila melanogaster. However, the internal molecular mechanisms behind the circadian clock remained a mystery until 1984, when Jeffrey C. Hall, Michael Rosbash, and Michael W. Young discovered the expression of the Per gene oscillating over a 24-hour cycle. In subsequent years,...
02:45Biological Clocks and Seasonal Responses
The circadian—or biological—clock is an intrinsic, timekeeping, molecular mechanism that allows plants to coordinate physiological activities over 24-hour cycles called circadian rhythms. Photoperiodism is a collective term for the biological responses of plants to variations in the relative lengths of dark and light periods. The period of light-exposure is called the photoperiod.
01:20The JAK-STAT Signaling Pathway
Several cytokine receptors have tightly bound Janus kinase or JAK proteins attached at their cytosolic tail. Small signaling molecules such as cytokines, growth hormones, or prolactins bind to the cytokine receptors and initiate their dimerization. The dimerization brings the cytosolic JAKs together that trans-phosphorylate and activates each other. The activated JAKs now phosphorylate cytosolic tails of the cytokine receptors, which serve as binding sites for adaptor proteins such as SH2...
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,...
02:32Histone 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,...