Video Experimental Relacionado
Updated: Dec 13, 2025

06:49
Nonradioactive Assay to Measure Polynucleotide Phosphorylation of Small Nucleotide Substrates
Published on: May 8, 2020
5.0K
ANGEL2 es un miembro de la familia CCR4 de las dedenilasas con actividad de 2',3'-fosfatasa cíclica
Paola H Pinto1, Alena Kroupova2, Alexander Schleiffer3
1Max Perutz Labs, Medical University of Vienna, Vienna BioCenter, 1030 Vienna, Austria.
Resumen
Los investigadores han identificado ANGEL2, una fosfatasa humana que elimina el 2
Área de la Ciencia:
- Biología molecular
- La bioquímica
- Metabolismo del ARN
Sus antecedentes:
- Las moléculas de ARN a menudo adquieren un grupo fosfato 2',3'-cíclico terminal a través de varios procesos celulares.
- Esta modificación es significativa en el procesamiento del ARN, particularmente en el ensamblaje del ARN previo a la transferencia (ARNt) y el ARN mensajero no convencional (ARNm), donde los fosfatos 2',3'-cíclicos son sustratos para el complejo de la ligasa del ARNt.
- La eliminación eficiente de estos fosfatos cíclicos es crucial para el reciclaje del tRNA, especialmente durante el estancamiento del ribosoma.
Objetivo del estudio:
- Identificar y caracterizar la enzima humana responsable de la hidrólisis de los fosfatos 2',3'-cíclicos.
- Investigar el papel de esta enzima en las vías clave de procesamiento de ARN.
- Aclarar la preferencia por el sustrato, la estructura y el mecanismo de reacción de la enzima identificada.
Principales métodos:
- Ensayos bioquímicos para analizar la preferencia del sustrato y la cinética de reacción de la fosfatasa identificada.
- Análisis estructural para determinar la estructura tridimensional de la enzima.
- Estudios funcionales que impliquen la perturbación de la expresión de la enzima para evaluar su impacto en las vías de procesamiento del ARN.
Principales resultados:
- Se identificó el homólogo 2 del ángel de la dedenilasa predicho (ANGEL2) como una fosfatasa humana que cataliza la conversión de fosfatos 2',3'-cíclicos en nucleótidos 2',3'-OH.
- Se analizaron la preferencia del sustrato, la estructura y el mecanismo de reacción de ANGEL2.
- Los niveles alterados de expresión de ANGEL2 afectaron el procesamiento pre- tRNA, el empalme de la proteína de unión a la caja X 1 (XBP1) durante la respuesta de la proteína desplegada, y la adición de CCA mediada por la tRNA nucleotidiltransferasa 1 (TRNT1).
Conclusiones:
- ANGEL2 juega un papel crítico en las vías metabólicas del ARN que implican la ligadura o la hidrólisis de fosfatos 2',3'-cíclicos.
- Esta fosfatasa es esencial para el procesamiento eficiente del ARNt previo y el empalme no convencional del ARNm.
- La función de ANGEL2 está relacionada con el reciclaje del ARNt y el mantenimiento de la homeostasis del ARN.
Videos de Conceptos Relacionados
Calmodulin-dependent Signaling
5.8K
Calmodulin (CaM) is a calcium-binding protein in eukaryotes that controls various calcium-regulated cellular processes. It has four calcium-binding sites that bind calcium to form the calcium-calmodulin ( Ca2+-CaM) complex. GPCR stimulation increases the calcium levels in the cells that bind to CaM and induces a conformational change.
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
5.8K
Anaphase Promoting Complex
3.2K
The stepwise destruction of specific proteins is necessary for the progression and completion of the cell cycle. Such proteins are ubiquitinated by ubiquitin ligases and then subsequently destroyed by the proteasome. The SCF (Skp1/Cullin/F-box) and the anaphase-promoting complex (APC) are two important ubiquitin ligases involved in cell cycle progression. While SCF is active throughout the cell cycle, APC gets activated during metaphase to anaphase transition. Cdc20 or Cdh1 binds to APC and...
3.2K
GPCRs Regulate Adenylyl Cylase Activity
6.8K
Some GPCRs transmit signals through adenylyl cyclase (AC), a transmembrane enzyme. AC helps synthesize second messenger cyclic adenosine monophosphate (cAMP). AC catalyzes cyclization reaction and converts ATP to cAMP by releasing a pyrophosphate. The pyrophosphate is further hydrolyzed to phosphate by the enzyme pyrophosphatase, which drives cAMP synthesis to completion. However, cAMP is rapidly degraded to 5′ AMP by the enzymes phosphodiesterase (PDE), preventing overstimulation of...
6.8K
Eukaryotic RNA Polymerases
26.3K
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...
All three eukaryotic RNAPs require specific transcription factors, of which the...
26.3K
RNA Editing
9.6K
RNA editing is a post-transcriptional modification where a precursor mRNA (pre-mRNA) nucleotide sequence is changed by base insertion, deletion, or modification. The extent of RNA editing varies from a few hundred bases, in mitochondrial DNA of trypanosomes, to a just single base, in nuclear genes of mammals. Even a single base change in the pre-mRNA can convert a codon for one amino acid into the codon for another amino acid or a stop codon. This type of re-coding can significantly affect the...
9.6K
mRNA Stability and Gene Expression
6.3K
The structure and stability of mRNA molecules regulates gene expression, as mRNAs are a key step in the pathway from gene to protein. In eukaryotes, the half-life of mRNA varies from a few minutes up to several days. mRNA stability is essential in growth and development. The absence of the proteins regulating its stability, such as tristetraprolin in mice, can cause systemic issues, including bone marrow overgrowth, inflammation, and autoimmunity.
Cis-acting Elements involved in mRNA stability
Cis-acting Elements involved in mRNA stability
6.3K

