Video Experimental Relacionado
Updated: Jul 13, 2026
10:17
Pulse-chase Analysis of N-linked Sugar Chains from Glycoproteins in Mammalian Cells
Published on: April 27, 2010
EDEM como aceptor de las glicoproteínas terminalmente mal plegadas liberadas por la calnexina
Yukako Oda1, Nobuko Hosokawa, Ikuo Wada
1Department of Molecular and Cellular Biology, Institute for Frontier Medical Sciences, Kyoto University, Kyoto 606-8397, Japan.
Science (New York, N.Y.)
|March 1, 2003
Resumen
La proteína EDEM acelera la degradación asociada al retículo endoplasmático (ERAD) al interactuar con la calnexina. Promueve la liberación de proteínas mal plegadas de la calnexina, facilitando su degradación proteasomal.
Área de la Ciencia:
- Biología celular Biología celular.
- La degradación de las proteínas.
- Función del retículo endoplasmático Función del retículo endoplasmático
Sus antecedentes:
- Las proteínas mal plegadas en el retículo endoplasmático (ER) se degradan a través de la degradación asociada a ER (ERAD).
- EDEM es una proteína implicada en la aceleración de ERAD, potencialmente mediante la unión a Man8B.
Objetivo del estudio:
- Para investigar la interacción de EDEM con las chaperonas de ER.
- Para aclarar el papel de EDEM en la vía ERAD.
Principales métodos:
- Pruebas de coinmunoprecipitación para estudiar las interacciones de las proteínas.
- Análisis de la cinética de ERAD tras la sobreexpresión de EDEM.
Principales resultados:
- EDEM interactúa con la calnexina a través de su región transmembrana, pero no con la calreticulina.
- La sobreexpresión de EDEM mejora la liberación de proteínas terminalmente mal plegadas de la calnexina.
- Tanto la unión a la calnexina como la liberación de sustratos son cruciales para ERAD.
Conclusiones:
- EDEM funciona dentro de la vía ERAD aceptando sustratos de la calnexina.
- EDEM actúa como un facilitador clave en el proceso de ERAD, promoviendo una rotación eficiente de proteínas.
Más Videos Relacionados
Videos de Conceptos Relacionados
01:28The Early Endosome: Endocytosis of Transferrin
Essential proteins such as insulin or low-density lipoprotein (LDL) and micronutrients such as iron enter a eukaryotic cell through receptor-mediated endocytosis. Subsequently, the early endosomes fuse with the vesicles containing such receptor-ligand complexes and play a vital role in sorting the incoming ligands and receptors. While the ligands are either degraded inside the vesicle or released into the cytosol, their receptors are returned to the plasma membrane for further rounds of...
01:45ER Retrieval Pathway
In the secretory pathway, vesicles transport proteins from one cellular compartment to another in forward transport to deliver the protein to its correct location. Occasionally, misfolded proteins and incorrect proteins escape their original compartments, and a retrieval pathway is used to return the escaped proteins to their original compartment.
The ER uses many checkpoints to prevent the entry of incorrectly folded or a resident protein as cargo onto a transport vesicle. These mechanisms...
The ER uses many checkpoints to prevent the entry of incorrectly folded or a resident protein as cargo onto a transport vesicle. These mechanisms...
01:24Oligosaccharide Assembly
Protein glycosylation starts in the ER lumen and continues in the Golgi apparatus. Glycosyltransferases catalyze the addition of sugar molecules or glycosylation of proteins. Usually, these enzymes add sugars to the hydroxyl groups of selected serine or threonine residues to form O-linked glycans or the amino groups of asparagine residues to form N-linked glycans. Different positions on the same polypeptide chain can contain differently linked glycans.
Multiple sugar molecules that may or may...
Multiple sugar molecules that may or may...
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...
01:05Insulin Secretory Vesicles
Insulin secretory vesicles release insulin to stimulate blood glucose uptake and regulate carbohydrate metabolism. When the blood glucose levels increase, glucose enters the pancreatic β-islet cells through glucose transporters. Once inside, glucose is metabolized through glycolysis, the citric acid cycle, and the electron transport chain, producing ATP. This increase in ATP concentration closes ATP-sensitive potassium channels, leading to depolarization of the membrane and the opening of...
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...