Video Experimental Relacionado
Updated: May 31, 2026
10:17
Pulse-chase Analysis of N-linked Sugar Chains from Glycoproteins in Mammalian Cells
Published on: April 28, 2010
Reciclaje selectivo del receptor de manosa 6-fosfato/IGF-II hacia la red trans Golgi in vitro
1Department of Biochemistry, Stanford University School of Medicine, California 94305-5307.
Cell
|October 21, 1988
Resumen
Los receptores de 6-fosfato de manosa se reciclan desde los prelissosomas hasta la red trans Golgi (TGN). Este transporte vesicular requiere hidrólisis de GTP y es distinto de otras vías de transporte de proteínas.
Área de la Ciencia:
- Biología celular Biología celular.
- Biología Molecular Biología Molecular
- La bioquímica es la bioquímica.
Sus antecedentes:
- Los receptores de manosa 6-fosfato (MPR) son cruciales para la clasificación de las enzimas lisosómicas.
- Las MPR transportan enzimas desde la red trans Golgi (TGN) hasta los prelissosomas y regresan a la TGN.
- Comprender el mecanismo de reciclaje de MPR es vital para la función celular.
Objetivo del estudio:
- Para investigar el transporte vesicular del receptor de manosa 6-fosfato/IGF-II desde los prelissosomas hasta el TGN in vitro.
- Para caracterizar los requisitos bioquímicos y la selectividad de esta vía de transporte.
Principales métodos:
- Desarrollo de un ensayo de complementación utilizando extractos celulares.
- La reconstitución in vitro del transporte vesicular.
- Caracterización bioquímica de las necesidades de transporte (hidrólisis GTP, sensibilidad a la primaquina).
Principales resultados:
- Se ha demostrado el transporte vesicular del receptor de manosa 6-fosfato/IGF-II desde los prelissosomas hasta el TGN en extractos celulares.
- Se mostró el transporte selectivo, con el receptor de transferrina que se mueve más lentamente que los MPR.
- Identificó la hidrólisis GTP como esencial para el reciclaje de MPR.
- Distinguido reciclaje de MPR desde el transporte constitutivo de Golgi a través de la resistencia a la primaquina.
Conclusiones:
- El estudio caracterizó con éxito el transporte vesicular in vitro de MPRs desde los prelissosomas hasta el TGN.
- El reciclaje de MPR es un proceso selectivo, dependiente de GTP, bioquímicamente distinto de otras vías de transporte.
- Estos hallazgos proporcionan información sobre los mecanismos moleculares de la clasificación de enzimas lisosomales y el reciclaje de receptores.
Videos de Conceptos Relacionados
00:58Recycling Endosomes and Transcytosis
The recycling endosome, also known as the endosomal recycling compartment (ERC), is a part of the slow-recycling process of the endocytic pathway. Molecules internalized through receptor-mediated endocytosis are either degraded in the lysosomes or are recycled to the plasma membrane through the fast- or slow-recycling route.
The recycling endosome is not a single organelle but an extensively tubulated network of recycling pathways. It functions in storing molecules or transporting them across...
The recycling endosome is not a single organelle but an extensively tubulated network of recycling pathways. It functions in storing molecules or transporting them across...
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...
01:15Receptor Downregulation in MVBs
Multivesicular bodies (MVBs) are mature endosomes that sort ubiquitinated proteins and then fuse with lysosomes to degrade the sorted proteins. Epidermal growth factor (EGF) and its receptor (EGFR) form a complex that can be internalized through endocytosis, sorted into an MVB, and later degraded.
The EGFR can initiate signaling pathways that lead to cell proliferation, migration, and differentiation. Overexpression of EGFR stimulates cells to proliferate. Excessive EGFR activation may...
The EGFR can initiate signaling pathways that lead to cell proliferation, migration, and differentiation. Overexpression of EGFR stimulates cells to proliferate. Excessive EGFR activation may...
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...