Video Experimental Relacionado

Updated: Aug 16, 2026

Drug-induced Sensitization of Adenylyl Cyclase: Assay Streamlining and Miniaturization for Small Molecule and siRNA Screening Applications

Drug-induced Sensitization of Adenylyl Cyclase: Assay Streamlining and Miniaturization for Small Molecule and siRNA Screening Applications

Published on: January 27, 2014

Un mecanismo general para la sinergia transcripcional por los activadores eucariotas

T Chi¹, P Lieberman, K Ellwood

¹Department of Biological Chemistry, University of California, Los Angeles, School of Medicine 90095-1737, USA.

|September 21, 1995

Resumen

La activación sinérgica de genes por activadores implica el ensamblaje estable del complejo TFIID:TFIIA. Este paso temprano en la formación del complejo de preiniciación mejora la actividad transcripcional mediante el reclutamiento de TFIIB.

Área de la Ciencia:

Biología Molecular Biología Molecular
Regulación genética Reglamento genético.
Virología Virología.

Sus antecedentes:

La expresión génica de los eucariotas depende de los promotores de la ARN polimerasa II y los activadores aguas arriba que funcionan como módulos.
La acción sinérgica de estos módulos regula la transcripción génica.
ZEBRA, un activador del virus Epstein-Barr (EBV), proporciona un modelo para el estudio de la sinergia del activador no ácido.

Objetivo del estudio:

Investigar el mecanismo bioquímico de la sinergia transcripcional mediada por los activadores.
Determinar el papel del conjunto complejo TFIID:TFIIA (DA) en la activación sinérgica de genes.
Explorar un mecanismo unificador para activadores ácidos y no ácidos.

Principales métodos:

Análisis bioquímico de los activadores de ZEBRA y GAL4-VP16.
Ensayos de huellas de DNase I.
Ensayos de cambio de gel para estudiar las interacciones proteína-ADN.

Principales resultados:

Los efectos transcripcionales sinérgicos se correlacionan con el ensamblaje del complejo TFIID:TFIIA (DA).
El complejo DA dependiente del activador exhibe una unión TFIIB estable, regulada por TAFs.
El enlace TFIIB mejora la sinergia al aumentar la estabilidad compleja.
Se observaron mecanismos similares para el activador ácido GAL4-VP16.

Conclusiones:

Se propone un mecanismo unificador para la activación de genes y la sinergia de diversos activadores.
La sinergia en la regulación transcripcional se manifiesta en la etapa inicial del ensamblaje del complejo de preiniciación.
El reclutamiento estable de TFIIB al complejo TFIID:TFIIA es crucial para la activación sinérgica de genes.

Más Videos Relacionados

An Integrated System to Remotely Trigger Intracellular Signal Transduction by Upconversion Nanoparticle-mediated Kinase Photoactivation

An Integrated System to Remotely Trigger Intracellular Signal Transduction by Upconversion Nanoparticle-mediated Kinase Photoactivation

Published on: August 30, 2017

A General Method for Detecting Nitrosamide Formation in the In Vitro Metabolism of Nitrosamines by Cytochrome P450s

A General Method for Detecting Nitrosamide Formation in the In Vitro Metabolism of Nitrosamines by Cytochrome P450s

Published on: September 25, 2017

Videos de Conceptos Relacionados

Neurochemical Transmission: Sites of Drug Action

Neurochemical Transmission: Sites of Drug Action

Neurochemical transmission, the conduction of electrical impulses between neurons mediated by neurotransmitters, plays a vital role in various physiological processes. Autonomic drugs exert their effects by modulating neurotransmission within the autonomic nervous system. For instance, drugs such as hemicholinium block the precursor uptake necessary for synthesizing acetylcholine, an essential autonomic neurotransmitter. Following synthesis, neurotransmitters are stored in vesicles. Metyrosine...

Indirect-Acting Cholinergic Agonists: Mechanism of Action

Indirect-Acting Cholinergic Agonists: Mechanism of Action

Indirect-acting cholinergic agonists work by interacting with an enzyme called acetylcholinesterase (AChE) in the synaptic cleft. They can be reversible or irreversible inhibitors and have different effects on the enzyme.
Reversible inhibitors like edrophonium bind to a specific part of the enzyme called the anionic catalytic site. They form noncovalent bonds, which means they are not strongly attached to the enzyme. This creates a temporary and less stable enzyme–inhibitor complex, leading to...

Drugs Acting on Autonomic Ganglia: Stimulants

Drugs Acting on Autonomic Ganglia: Stimulants

Ganglionic stimulants activate NM nicotinic receptors in autonomic ganglia, falling into two categories: nicotine mimetics [e.g., lobeline, dimethylpiperazine, tetramethylammonium] and muscarinic receptor agonists [e.g., muscarine, methacholine]. The first category's action is rapid and blocked by nicotinic receptor antagonists, while the second category's action is delayed and blocked by atropine-like agents. Nicotine, an alkaloid, affects the heart rate by stimulating sympathetic or...

Drugs Affecting Neurotransmitter Release or Uptake

Drugs Affecting Neurotransmitter Release or Uptake

Certain drugs can affect how neurotransmitters called catecholamines, are released or taken back up in the adrenergic neuron. They can have different effects on the body's sympathetic transmission. Reserpine, a natural compound found in the Rauwolfia shrub, blocks a transporter called vesicular monoamine transporter (VMAT), which leads to a buildup of catecholamines in the cell and reduces sympathetic transmission. Another drug called guanethidine works in multiple ways, including blocking...

Active Transport

Active Transport

Active transport is a critical biological process that allows cells to move solutes against an electrochemical gradient. This process requires direct energy input and is characterized by its selectivity, saturability, and susceptibility to competitive inhibition.
Primary active transporters, like Na+, K+ and -ATPase, directly utilize ATP to move ions across the membrane. These transporters play significant roles in various physiological processes. For instance, Na+, K+ and -ATPase maintain...

Renal Drug Excretion: Tubular Secretion

Renal Drug Excretion: Tubular Secretion

Active tubular secretion is a robust, energy-demanding process that utilizes carrier systems to transport drugs into renal tubules. The active renal secretion systems include the organic anion transporter (OAT) for weak acids and the organic cation transporter (OCT) for weak bases. Structurally similar drugs can compete for the same transporter, potentially leading to drug accumulation and toxicity. However, this principle can be exploited therapeutically. One example is probenecid (Probalan),...