Video Experimental Relacionado
Updated: Mar 14, 2026
12:43
Genetic and Biochemical Approaches for In Vivo and In Vitro Assessment of Protein Oligomerization: The Ryanodine Receptor Case Study
Published on: July 27, 2016
12.2K
Bases estructurales para la puesta en marcha y la activación de RyR1
Amédée des Georges1, Oliver B Clarke2, Ran Zalk3
1Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA; Howard Hughes Medical Institute, Columbia University, New York, NY 10032, USA.
Cell
|September 24, 2016
Resumen
La estructura del receptor de ryanodina tipo 1 (RyR1) revela cómo el calcio y la unión al ATP controlan la contracción muscular. Cryo-EM muestra que la entrada de RyR1 implica cambios conformacionales globales y locales, lo que explica la activación del canal.
Área de la Ciencia:
- La bioquímica
- Biología estructural
- Fisiología molecular
Sus antecedentes:
- El receptor de ryanodina tipo 1 (RyR1) es un canal crítico de liberación de calcio intracelular.
- RyR1 es esencial para la contracción del músculo esquelético, regulando la dinámica del calcio.
Objetivo del estudio:
- Para aclarar los mecanismos estructurales subyacentes a la apertura y activación del canal RyR1.
- Para identificar sitios de unión para activadores clave como el calcio (Ca2+), el ATP y la cafeína.
Principales métodos:
- Reconstrucciones de cryoelectron microscopy (cryo-EM) de RyR1 en varios estados funcionales.
- Análisis estructural de alta resolución de los estados abiertos y cerrados de RyR1.
Principales resultados:
- Sitios de unión identificados para Ca2+, ATP y cafeína en las interfaces de dominio C-terminal.
- Ca2+ observado o ATP por sí solo induce cambios conformacionales de "priming" sin dilatación de los poros.
- Se reveló que el encierro de RyR1 implica cambios citosólicos globales y alteraciones locales del dominio transmembrana, incluida la flexión S6 y la dilatación de los poros.
Conclusiones:
- El estudio proporciona una comprensión estructural detallada de la entrada y activación de RyR1.
- Los cambios conformacionales en RyR1, impulsados por la unión de ligandos, son cruciales para la función del músculo esquelético.
Palabras clave:
- ¿Qué es eso?liberación de calcioCrio-EMAcoplamiento por contracción por excitaciónpuertasLas demás sustanciasreconstrucción de una sola partículaLa estructuraMás Videos Relacionados
Videos de Conceptos Relacionados
01:30Ligand-Gated Ion Channel Receptor: Gating Mechanism
4.6K
Ligand-gated ion channels are transmembrane proteins that play a vital role in intercellular communication and functions of the nervous system. They allow the influx of ions across the membrane once the neurotransmitter binds, allowing the subsequent transmission of electrical excitation across the neurons. Other ligand-gated ion channels, like the γ-aminobutyric acid (GABA) receptor, permit anions like chloride into the cells on the binding of the GABA molecule. Their entry into the cell...
4.6K
01:22Activation and Inactivation of G Proteins
12.1K
Heterotrimeric G proteins are guanine nucleotide-binding proteins. As the name suggests, heterotrimeric G proteins are composed of three subunits: alpha, beta, and gamma. They remain GDP-bound or GTP-bound inside the cells and switch between inactive/active states. The Gα subunit possesses the nucleotide-binding pocket that binds guanine nucleotides and switches between GDP or GTP-bound states. In contrast, the Gꞵ and Gγ subunits are always bound together with high...
12.1K
01:09GPCRs Regulate Adenylyl Cylase Activity
8.0K
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...
8.0K
01:21G-Protein Gated Ion Channels
6.6K
GPCRs are primarily responsible for our sense of smell, taste, and vision. The binding of a sensory stimulus activates GPCR to stimulate effector proteins, many of which are ion channels in the sensory organs. GPCRs modulate the opening and closing of the target ion channels either directly by binding them, or by releasing second messengers that activate these channels. As ions move across the membrane, the membrane potential is altered, which induces an appropriate response.
Sensory...
Sensory...
6.6K
01:22Amplifying Signals via Enzymatic Cascade
19.0K
When a ligand binds to a cell-surface receptor, the receptor's intracellular domain changes shape, which may either activate its enzyme function or allow its binding to other molecules. The initial signal is amplified by most signal transduction pathways. This means that a single ligand molecule can activate multiple molecules of a downstream target. Proteins that relay a signal are most commonly phosphorylated at one or more sites, activating or inactivating the protein. Kinases catalyze...
19.0K
01:26Receptor Tyrosine Kinases
20.3K
Receptor tyrosine kinases or RTKs are membrane-bound receptors that phosphorylate specific tyrosine on protein substrates. RTKs regulate cellular growth, differentiation, survival, and migration. They contain an extracellular ligand binding domain, a transmembrane domain, and a cytosolic tail with intrinsic kinase activity. Several extracellular signaling molecules activate RTKs in one or more ways and relay the signal downstream. Ligands such as platelet-derived growth factor (PDGF) or...
20.3K