Video Experimental Relacionado
Updated: May 10, 2026
08:59
4D Imaging of Protein Aggregation in Live Cells
Published on: April 5, 2013
El plegamiento mediado por GroEL/GroES de una proteína demasiado grande para ser encapsulada
T K Chaudhuri1, G W Farr, W A Fenton
1Howard Hughes Medical Institute, Department of Genetics, Yale University School of Medicine, Boyer Center, New Haven, CT 06510, USA.
Cell
|October 24, 2001
Resumen
Las chaperoninas GroEL y GroES ayudan al plegamiento de la aconitasa mitocondrial a través de un nuevo mecanismo que implica la liberación del sustrato para el plegamiento de la solución, no la encapsulación cis. Este proceso es crucial para la función y estabilidad de las enzimas.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Biología Molecular Biología Molecular
- Biología celular Biología celular.
Sus antecedentes:
- La chaperonina GroEL ayuda al plegamiento de las proteínas, pero su mecanismo para sustratos demasiado grandes para la cavidad cis no está claro.
- La aconitasa mitocondrial, una enzima de clúster de hierro-azufre, se agrega en las células deficientes de chaperonina, lo que sugiere un papel para las chaperoninas en su estabilidad.
Objetivo del estudio:
- Investigar el mecanismo por el cual las chaperoninas GroEL y GroES facilitan el plegamiento de la aconitasa mitocondrial de levadura.
- Para determinar si el plegamiento de la aconitasa implica encapsulación cis o una vía alternativa.
Principales métodos:
- Ensayos de plegado in vivo e in vitro de la aconitasa mitocondrial de la levadura.
- Utilizó GroEL y GroES chaperoninas en presencia y ausencia de ATP y cofactores.
- Dinámica de unión, liberación y replegamiento de proteínas observada.
Principales resultados:
- El plegamiento de la aconitasa requiere tanto GroEL como GroES, procediendo a través de múltiples ciclos de unión y liberación.
- El plegado no implica encapsulación cis; en su lugar, GroES que se une al anillo trans libera aconitasa para el plegado de la solución.
- GroEL se une a la apoaconitasa después del repliegue, liberando la holoenzima activa sobre la formación del cofactor Fe ((4) S ((4), independiente del ATP / GroES.
Conclusiones:
- Las chaperoninas GroEL/GroES emplean un mecanismo no canónico para el plegamiento de sustratos grandes, liberando el sustrato para el replegamiento extracelular.
- Este mecanismo es esencial para prevenir la agregación y asegurar el correcto plegamiento y función de la aconitasa mitocondrial.
- La etapa final de maduración implica la liberación mediada por GroEL de la holoenzima activa después de la incorporación del cofactor.
Videos de Conceptos Relacionados
01:22Protein Folding
Overview
03:00Molecular Chaperones and Protein Folding
The native conformation of a protein is formed by interactions between the side chains of its constituent amino acids. When the amino acids cannot form these interactions, the protein cannot fold by itself and needs chaperones. Notably, chaperones do not relay any additional information required for the folding of polypeptides; the native conformation of a protein is determined solely by its amino acid sequence. Chaperones catalyze protein folding without being a part of the folded protein.
The...
The...
01:29Protein Folding Quality Check in the RER
ER is the primary site for the maturation and folding of soluble and transmembrane secretory proteins. The calnexin cycle is a specific chaperone system that folds and assesses the confirmation of N-glycosylated proteins before they can exit the ER lumen. The primary players of this quality check pipeline are the lectins, ER-resident chaperones, and a glucosyl transferase enzyme. In case the calnexin system in the lumen fails to salvage a misfolded protein, it is transported to the cytoplasm...
01:32Export of Misfolded Proteins out of the ER
After folding, the ER assesses the quality of secretory and membrane proteins. The correctly folded proteins are cleared by the calnexin cycle for transport to their final destination, while misfolded proteins are held back in the ER lumen. The ER chaperones attempt to unfold and refold the misfolded proteins but sometimes fail to achieve the correct native conformation. Such terminally misfolded proteins are then exported to the cytosol by ER-associated degradation or ERAD pathway for...
01:25Protein Folding
Proteins are chains of amino acids linked together by peptide bonds. Upon synthesis, a protein folds into a three-dimensional conformation, critical to its biological function. Interactions between its constituent amino acids guide protein folding, and hence the protein structure is primarily dependent on its amino acid sequence.
Protein Structure Is Critical to Its Biological Function
Proteins perform a wide range of biological functions such as catalyzing chemical reactions, providing...
Protein Structure Is Critical to Its Biological Function
Proteins perform a wide range of biological functions such as catalyzing chemical reactions, providing...
03:00Molecular Chaperones and Protein Folding
The native conformation of a protein is formed by interactions between the side chains of its constituent amino acids. When the amino acids cannot form these interactions, the protein cannot fold by itself and needs chaperones. Notably, chaperones do not relay any additional information required for the folding of polypeptides; the native conformation of a protein is determined solely by its amino acid sequence. Chaperones catalyze protein folding without being a part of the folded protein.
The...
The...