関連する実験動画
Updated: May 31, 2026
10:17
Pulse-chase Analysis of N-linked Sugar Chains from Glycoproteins in Mammalian Cells
Published on: April 28, 2010
マノース6フォスファート/IGF-II受容体の選択的リサイクリングをトランス・ゴルギネットワークにインビトロで行う
1Department of Biochemistry, Stanford University School of Medicine, California 94305-5307.
Cell
|October 21, 1988
まとめ
マノース6リン酸受容体はプレライソソームからトランスゴルギネットワーク (TGN) に再利用されます. この膀輸送はGTPの水解を必要とし,他のタンパク質輸送経路とは異なる.
科学分野:
- 細胞生物学 細胞生物学
- 分子生物学は分子生物学である.
- バイオケミストリー バイオケミストリー
背景:
- マノース6リン酸受容体 (MPR) は,リソソーム酵素の分類に不可欠です.
- MPRは,トランス・ゴルギ・ネットワーク (TGN) からプレライソソームに酵素を輸送し,TGNに戻します.
- MPRリサイクルのメカニズムを理解することは,細胞機能にとって不可欠です.
研究 の 目的:
- マノース6フォスファート/IGF-II受容体のプレライソソームからTGNへの膀輸送を in vitroで調査する.
- この輸送経路の生化学的要件と選択性を特徴づける.
主な方法:
- 細胞抽出物を用いた補完測定法の開発.
- 膀輸送のインビトロ再構成.
- 輸送要求の生化学的特徴付け (GTP水解,プリマキンの感受性).
主要な成果:
- マノース6フォスファート/IGF-II受容体のプレライソソームからTGNへの膀輸送が細胞抽出物で実証された.
- 選択的輸送が示され,トランスファーリン受容体はMPRよりもゆっくり動く.
- MPRリサイクルに不可欠なGTP水解を特定しました.
- プリマキン耐性経由による構成的なゴルギ輸送からの優れたMPRリサイクリング.
結論:
- この研究では,プレライソソームからTGNへのMPRのインビトロ膀輸送を成功裏に特徴づけました.
- MPRのリサイクルは,他の輸送経路と生化学的に異なる選択的,GTPに依存するプロセスです.
- これらの発見は,リゾソーム酵素の分類と受容体のリサイクルにおける分子機構の洞察を提供します.
関連する概念動画
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...