Video Experimental Relacionado

Updated: Feb 10, 2026

In vitro Reconstitution of the Active T. castaneum Telomerase

In vitro Reconstitution of the Active T. castaneum Telomerase

Published on: July 14, 2011

Un interruptor de actividad en la telomerasa humana basado en la conformación del ARN y moldeado por TCAB1

Lu Chen¹, Caitlin M Roake¹, Adam Freund¹

¹Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA; Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA 94305, USA.

|May 29, 2018

Resumen

La actividad de la telomerasa depende de la proteína TCAB1, que controla la conformación del ARN de la telomerasa humana (hTR). Esto revela un interruptor que regula la catálisis de la telomerasa y la unión a TERT, lo que afecta el cáncer y la biología de las células madre.

Área de la Ciencia:

Biología molecular
La bioquímica
La genética

Sus antecedentes:

Las enzimas ribonucleoproteicas requieren estructuras dinámicas de ARN para la catálisis.
La telomerasa humana (hTR) tiene un núcleo y una unión CR4/5 que estimula la catálisis a través de mecanismos desconocidos.

Objetivo del estudio:

Para aclarar el papel de TCAB1 en la actividad de la telomerasa humana.
Comprender cómo TCAB1 influye en la conformación del dominio CR4/5 de hTR.
Investigar el vínculo entre la conformación CR4/5, la unión a TERT y la catálisis de la telomerasa.

Principales métodos:

Se estudió la actividad de la telomerasa en las células que carecen de TCAB1.
Se analizaron los cambios conformacionales en las hélices CR4/5 tras la inactivación de TCAB1.
Se examinaron los efectos de las mutaciones CR4/5 derivadas de los pacientes en la función de la telomerasa.

Principales resultados:

TCAB1 es esencial para la catálisis de la telomerasa, independiente del ensamblaje de la enzima.
El agotamiento de TCAB1 causa el despliegue de las hélices CR4/5, lo que afecta la asociación TERT.
Las mutaciones CR4/5 imitan los efectos de la inactivación de TCAB1 en la catálisis y en la unión a TERT.

Conclusiones:

TCAB1 actúa como un regulador crucial de la telomerasa mediante el control de la conformación hTR CR4/5.
Un interruptor conformacional en hTR rige la catálisis de la telomerasa y el compromiso de TERT.
Dos estados catalíticos distintos de la telomerasa sugieren una regulación intramolecular relevante para el cáncer y las células progenitoras.

Palabras clave:

Caja CAB CR4/5 (en inglés)Cuerpo de Cajal H/ACA RNP El plegamiento del ARN TCAB1 (en inglés)Disqueratosis congénita el icSHAPE La telomerasa Los telómeros

Más Videos Relacionados

Semi-quantitative Detection of RNA-dependent RNA Polymerase Activity of Human Telomerase Reverse Transcriptase Protein

Semi-quantitative Detection of RNA-dependent RNA Polymerase Activity of Human Telomerase Reverse Transcriptase Protein

Published on: June 12, 2018

Telomere Length and Telomerase Activity; A Yin and Yang of Cell Senescence

Telomere Length and Telomerase Activity; A Yin and Yang of Cell Senescence

Published on: May 22, 2013

Videos de Conceptos Relacionados

Telomeres and Telomerase

Telomeres and Telomerase

In eukaryotic DNA replication, a single-stranded DNA fragment remains at the end of a chromosome after the removal of the final primer. This section of DNA cannot be replicated in the same manner as the rest of the strand because there is no 3’ end to which the newly synthesized DNA can attach. This non-replicated fragment results in gradual loss of the chromosomal DNA during each cell duplication. Additionally, it can induce a DNA damage response by enzymes that recognize single-stranded...

Telomeres and Telomerase

Telomeres and Telomerase

Conformity

Conformity

Conformity is the change in a person’s behavior to go along with the group, even if that person does not agree with the group.

Switching of BJT

Switching of BJT

Switching behavior in Bipolar Junction Transistors (BJTs) is a fundamental aspect utilized in various electronic circuits, particularly for digital logic applications like switches and amplifiers. In a typical switching circuit, a BJT alternates between cut-off and saturation modes, corresponding to the "off" and "on" states, respectively, thus behaving like an ideal switch.
Cut-off Mode ("Off" State): In this state, both the emitter-base and collector-base junctions are...

Eukaryotic RNA Polymerases

Eukaryotic RNA Polymerases

RNA Polymerase (RNAP) is conserved in all animals, with bacterial, archaeal, and eukaryotic RNAPs sharing significant sequence, structural, and functional similarities. Among the three eukaryotic RNAPs, RNA Polymerase II is most similar to bacterial RNAP in terms of both structural organization and folding topologies of the enzyme subunits. However, these similarities are not reflected in their mechanism of action.
All three eukaryotic RNAPs require specific transcription factors, of which the...

Conformations of Butane

Conformations of Butane

Unlike ethane and propane that have only two major conformations, butane has more than two conformers. The staggered form of butane in which the bulky methyl groups on the two carbons are placed on opposite sides, that is, at a dihedral angle of 180°, is the lowest energy, most stable form — called the anti conformer. This conformation is stabilized due to the absence of steric repulsion between the largely spaced out methyl groups. The other two staggered conformations are...