Video Experimental Relacionado
Updated: Aug 17, 2025
07:38
Functional Characterization of Na+/H+ Exchangers of Intracellular Compartments Using Proton-killing Selection to Express Them at the Plasma Membrane
Published on: March 30, 2015
9.3K
Conocimientos estructurales sobre el mecanismo del simportador de sodio y yoduro
Silvia Ravera1, Juan Pablo Nicola2, Glicella Salazar-De Simone3
1Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA.
Nature
|December 14, 2022
Resumen
La estructura de simportador de sodio y yoduro (NIS) revela cómo transporta iones de yoduro y sodio, cruciales para la producción de hormonas tiroideas y el tratamiento del cáncer por radioioduro. Esto proporciona un marco para comprender la función de NIS y el transporte de sustratos.
Área de la Ciencia:
- La bioquímica
- Biología molecular
- Biología estructural
Sus antecedentes:
- El simportador de sodio y yoduro (NIS) es vital para la síntesis de hormonas tiroideas y el tratamiento del cáncer con radioioduro.
- El NIS facilita el transporte de yoduro junto con iones de sodio a través de la membrana plasmática.
- Las mutaciones en NIS conducen a hipotiroidismo congénito, lo que requiere tratamiento precoz.
Objetivo del estudio:
- Determinar las estructuras del NIS de la rata en diferentes estados ligados al sustrato.
- Elucidar los mecanismos moleculares del transporte de iones mediado por NIS y la unión al sustrato.
- Proporcionar un marco estructural para comprender la función del NIS y la selectividad del sustrato.
Principales métodos:
- Se utilizó la criomicroscopia electrónica de una sola partícula (cryo-EM) para determinar las estructuras de NIS.
- Se realizaron estudios de caracterización funcional y computacional.
- Análisis de las estructuras NIS con y sin sustratos unidos (Na+, I-, perrenato).
Principales resultados:
- Se resolvieron tres estructuras distintas de NIS en ratas: apo, Na+/I- unido y Na+/perrenato unido.
- Se identificaron los principales residuos y sitios de unión al sustrato implicados en la actividad de transporte.
- Se obtuvieron conocimientos sobre los mecanismos de selección, acoplamiento y translocación de aniones.
Conclusiones:
- Las estructuras NIS determinadas ofrecen un marco para comprender su mecanismo de transporte.
- Los hallazgos explican cómo el NIS selecciona, acopla y transloca aniones con diferentes estequiometrías.
- Esta investigación ilumina los mecanismos de liberación de sustrato desde la cavidad de unión en el citosol.
Más Videos Relacionados
Videos de Conceptos Relacionados
01:29Primary Active Transport
10.6K
In contrast to passive transport, active transport involves a substance being moved through membranes in a direction against its concentration or electrochemical gradient. There are two types of active transport: primary active transport and secondary active transport. Primary active transport utilizes chemical energy from ATP to drive protein pumps embedded in the cell membrane. With energy from ATP, the pumps transport ions against their electrochemical gradients—a direction they would...
10.6K
01:32Secondary Active Transport
7.3K
One example of how cells use the energy contained in electrochemical gradients is demonstrated by glucose transport into cells. The ion vital to this process is sodium (Na+), which is typically present in higher concentrations extracellularly than in the cytosol. Such a concentration difference is due, in part, to the action of an enzyme "pump" embedded in the cellular membrane that actively expels Na+ from a cell. Importantly, as this pump contributes to the high concentration of...
7.3K
01:17Reabsorption and Secretion in the Loop of Henle
1.6K
The thick ascending limb of the nephron loop has Na+–K+–2Cl− symporters in the apical membranes of its cells. These symporters simultaneously reclaim one sodium ion, one potassium ion, and two chloride ions from the tubular fluid. Sodium ions are actively transported into the interstitial fluid at the base and sides of the cell, diffusing into the vasa recta. Chloride ions move through leakage channels in the basolateral membrane into the interstitial fluid and then into the...
1.6K
01:44The Significance of Membrane Transport
28.4K
The transport of solutes across the cell membrane is essential for metabolic processes, like maintaining cell size and volume, generating the action potential, exchanging nutrients and gases, etc. Membrane transport can be either passive or active. It can be simple diffusion, facilitated, or mediated transport aided by transport proteins such as transporters and channels.
Transporters facilitate either an active or passive movement of solutes. They can allow a single-molecule transport down its...
Transporters facilitate either an active or passive movement of solutes. They can allow a single-molecule transport down its...
28.4K
01:16Facilitated Diffusion
540
The plasma membrane, a critical structure in cellular biology, houses an array of transporters, or carrier proteins, interspersed within its lipid bilayer. These proteins play a crucial role in solute transport through facilitated diffusion, a form of passive diffusion that uses transporters to move the molecules across the membrane.
In this process, substrates such as organic compounds and ions interact with a transporter on one side, triggering conformational changes in proteins that enable...
In this process, substrates such as organic compounds and ions interact with a transporter on one side, triggering conformational changes in proteins that enable...
540
01:14Active Transport
796
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...
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...
796