Video Experimental Relacionado
Updated: Aug 5, 2026
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
Clonación de expresión y caracterización de un cotransportador renal electrogénico Na+/HCO3-
M F Romero1, M A Hediger, E L Boulpaep
1Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut 06510, USA. mromero@biomed.med.yale.edu
Nature
|May 22, 1997
Resumen
Los investigadores identificaron un nuevo cotransportador de bicarbonato de sodio (NBC, por sus siglas en inglés). Este transportador electrogénico es crucial para la regulación del pH en las células animales, particularmente en el riñón, y ha sido clonado y caracterizado con éxito.
Área de la Ciencia:
- Fisiología Fisiología Fisiología.
- Biología Molecular Biología Molecular
- La bioquímica es la bioquímica.
Sus antecedentes:
- Los transportadores de bicarbonato son reguladores clave del pH intracelular en las células animales.
- Son vitales para el equilibrio ácido-base en varios órganos, incluido el riñón.
- El conocimiento de muchos transportadores de bicarbonato, especialmente los acoplados a cationes, sigue siendo limitado.
Objetivo del estudio:
- Clonar y caracterizar un nuevo transportador de bicarbonato acoplado a cationes.
- Para identificar la base molecular del cotransportador renal de bicarbonato de sodio (NBC) electrogénico.
Principales métodos:
- Monitoreo del pH intracelular y la tensión de la membrana en los ovocitos de Xenopus.
- Clonado y expresión de un ADNc candidato que codifica un transportador de bicarbonato.
- Caracterización funcional de la proteína expresada, incluida la dependencia iónica y la sensibilidad al inhibidor.
Principales resultados:
- Clonado exitoso y caracterización de un ADNc codificando una proteína de 1.035 aminoácidos.
- La expresión en los ovocitos de Xenopus confirmó que la proteína es electrogénica, dependiente del sodio (Na+) y el bicarbonato (HCO3-).
- La actividad del transportador fue inhibida por DIDS, consistente con el transporte de bicarbonato.
Conclusiones:
- El ADNc clonado codifica el cotransportador renal electrogénico de bicarbonato de sodio (NBC).
- Este hallazgo avanza en la comprensión de los mecanismos de regulación del pH en la fisiología animal.
- El estudio proporciona una base molecular para un transportador crítico involucrado en la homeostasis ácido-base.
Videos de Conceptos Relacionados
01:47Primary Active Transport
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 that are embedded in the cell membrane. With energy from ATP, the pumps transport ions against their electrochemical gradients—a direction they...
01:55Secondary Active Transport
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...
01:29Primary Active Transport
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 not...
01:32Secondary Active Transport
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...
01:17Reabsorption and Secretion in the Loop of Henle
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 vasa recta.
01:22Physiology of the Genitourinary System II: Tubular Reabsorption and Secretion
The kidneys maintain homeostasis through filtration, reabsorption, and secretion. Tubular reabsorption and secretion are crucial in forming urine and regulating electrolytes, water balance, and waste elimination.Tubular Reabsorption and Secretion ProcessesTubular reabsorption is the process that reclaims essential substances such as electrolytes, glucose, amino acids, and water from the glomerular filtrate back into the bloodstream. This is achieved through passive and active transport...