Video Experimental Relacionado
Updated: May 16, 2026
07:17
Single-Cell Calcium Imaging for Studying the Activation of Calcium Ion Channels
Published on: December 13, 2024
Estructura cristalina del canal de calcio activado por la liberación de calcio Orai
Xiaowei Hou1, Leanne Pedi, Melinda M Diver
1Structural Biology Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA.
Science (New York, N.Y.)
|November 28, 2012
Resumen
La proteína Orai forma el poro del canal de calcio activado por la liberación de calcio (CRAC). Su estructura cristalina revela un ensamblaje hexameric, ofreciendo información sobre la permeación del calcio y los mecanismos de encierro.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Biología Estructural Biología estructural.
- Fisiología Molecular Fisiología Molecular.
Sus antecedentes:
- Orai es una proteína de membrana plasmática crucial para la función del canal de calcio activado por liberación de calcio (CRAC).
- Los canales CRAC median las señales de calcio citosólico sostenido sobre la depleción de calcio en el retículo endoplasmático.
Objetivo del estudio:
- Para determinar la estructura cristalina de la proteína Orai de Drosophila melanogaster.
- Para dilucidar las bases estructurales de la arquitectura del canal CRAC, la permeación iónica y el gating.
Principales métodos:
- Cristalografía de rayos X con una resolución de 3,35 angstroms.
Principales resultados:
- El canal Orai es un conjunto hexamericano que rodea un poro iónico central.
- Un anillo de glutamato en el lado extracelular actúa como el filtro de selectividad.
- Una región intracelular básica puede unir aniones, potencialmente estabilizando el estado cerrado.
Conclusiones:
- La arquitectura del canal Orai es distinta de la de otros canales iónicos.
- Se proporcionan conocimientos estructurales sobre la permeación selectiva de calcio y los principios de encierro.
Más Videos Relacionados
Videos de Conceptos Relacionados
01:16Calmodulin-dependent Signaling
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,...
01:27Feedback Regulation of Calcium Concentration
Calcium is an essential signaling molecule required for various cellular functions. Calcium pumps and ion channels on cell and organellar membranes, such as those on the endoplasmic reticulum (ER), regulate calcium concentrations inside the cell. They remain closed, keeping the cytosolic calcium levels low at a resting state.
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
01:30Ligand-Gated Ion Channel Receptor: Gating Mechanism
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...
01:25Structure of Cadherins
The cadherins were one of the first cell adhesion molecules discovered; the term “cadherins” is based on their calcium-dependent adhering properties. The first cadherins discovered on the epithelial, neuronal, and placental cells were named E-cadherin, P-cadherin, and N-cadherin, respectively. These classical cadherins share sequence and structural similarities. Other cadherins, including those involved in cell signaling, are grouped into non-classical cadherins. This diversity of cadherins...
01:19Ligand-gated Ion Channels
Ligand-gated ion channels are transmembrane proteins with a channel for ions to pass through and a binding site for a ligand. The channel opens only when a ligand attaches to the binding site.
Three Subfamilies of Ligand-gated Ion Channels
Ligand-gated ion channels fall into three subfamilies. The 'Cys-loop' includes the nicotinic acetylcholine receptors, γ-aminobutyric acid (GABA), glycine, and 5-hydroxytryptamine receptors. The second one is the 'Pore-loop' channels that include the...
Three Subfamilies of Ligand-gated Ion Channels
Ligand-gated ion channels fall into three subfamilies. The 'Cys-loop' includes the nicotinic acetylcholine receptors, γ-aminobutyric acid (GABA), glycine, and 5-hydroxytryptamine receptors. The second one is the 'Pore-loop' channels that include the...
01:19Ligand-gated Ion Channels
Ligand-gated ion channels are transmembrane proteins with a channel for ions to pass through and a binding site for a ligand. The channel opens only when a ligand attaches to the binding site.
Three Subfamilies of Ligand-gated Ion Channels
Ligand-gated ion channels fall into three subfamilies. The 'Cys-loop' includes the nicotinic acetylcholine receptors, γ-aminobutyric acid (GABA), glycine, and 5-hydroxytryptamine receptors. The second one is the 'Pore-loop' channels that include the...
Three Subfamilies of Ligand-gated Ion Channels
Ligand-gated ion channels fall into three subfamilies. The 'Cys-loop' includes the nicotinic acetylcholine receptors, γ-aminobutyric acid (GABA), glycine, and 5-hydroxytryptamine receptors. The second one is the 'Pore-loop' channels that include the...