関連する実験動画
Updated: May 12, 2026
04:56
Epithelial Cell Infection Analyses with Shigella
Published on: February 9, 2024
シゲラ菌の毒性因子IpaJJによるN-ミリスタイル変異のプロテオリチクな除去
Nikolay Burnaevskiy1, Thomas G Fox, Daniel A Plymire
1Department of Microbiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-8816, USA.
Nature
|March 29, 2013
まとめ
Shigella flexneriの侵入性プラズミド抗原J (IpaJ) は,宿主タンパク質からN-ミリスチロールの改変を取り除きます. このデミリストイレーションは宿主細胞のシグナル伝達と分泌を妨害し,新しい細菌の病原性メカニズムを明らかにします.
科学分野:
- 分子生物学は分子生物学である.
- 細胞生物学 細胞生物学
- 微生物学 微生物学とは
背景:
- タンパク質のN-ミリストイレーションは,タンパク質機能と細胞シグナル伝達に不可欠な保存された改変である.
- ミリスチル基は,重要なタンパク質とタンパク質,およびタンパク質と膜の相互作用を媒介する.
- 病原性バクテリアは,宿主細胞を操作するために,タンパク質の修正をターゲットにすることができます.
研究 の 目的:
- 宿主タンパク質の機能を改変する新たな細菌エフェクタータンパク質を特定し,特徴づけること.
- Shigella flexneri IpaJが宿主細胞のプロセスに影響を与えるメカニズムを解明する.
- 細菌の病原性におけるタンパク質デミリストイレーションの役割を調査する.
主な方法:
- IpaJ基板を特定するための酵母遺伝子スクリーニング.
- タンパク質分裂部位を分析するための質量スペクトロメトリ.
- タンパク質酵素の活性と基板特異性を確認するための生化学的測定法.
主要な成果:
- Shigella flexneri 侵入性プラズミド抗原J (IpaJ) はシステインタンパク質酶として特定されました.
- IpaJは,ADP-リボシライゼーションファクター1 (ARF1) を含む,N-ミリスチル化タンパク質を特に割ります.
- IpaJ媒介によるデミリストイレーションは宿主細胞の分泌を阻害し,様々な細胞機能に影響します.
結論:
- IpaJは,宿主細胞のシグナル伝達を妨害するために,サイト特異のタンパク質デミリストイレーションという新しいメカニズムを採用しています.
- このバクテリアの戦略は,宿主分泌経路の阻害のための新しい道筋を提供します.
- 発見は,N-ミリスタイルタンパク質の改変の除去を含む未知の病原性メカニズムを明らかにしています.
関連する概念動画
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...
01:13The Proteasome
Eukaryotic cells can degrade proteins through several pathways. One of the most important among these is the ubiquitin-proteasome pathway. It helps the cell eliminate the misfolded, damaged, or unwarranted cytoplasmic proteins in a highly specific manner.
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. This involves participation of a series of enzymes including— E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3 (ubiquitin...
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. This involves participation of a series of enzymes including— E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3 (ubiquitin...
02:18The Proteasome
Eukaryotic cells can degrade proteins through several pathways. One of the most important amongst these is the ubiquitin-proteasome pathway. It helps the cell eliminate the misfolded, damaged, or unwarranted cytoplasmic proteins in a highly specific manner.
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. A series of enzymes carry out the ubiquitination of the target proteins - E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. A series of enzymes carry out the ubiquitination of the target proteins - E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...
02:58Regulated Protein Degradation
It is vital to regulate the activity of enzymatic as well as non-enzymatic proteins inside the cell. This can be achieved either through creating a balance between their rate of synthesis and degradation or regulating the intrinsic activity of the protein. Both these regulation mechanisms play an essential role in the normal functioning of cells.
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
01:18Bacterial Gastroenteritis
Bacterial gastroenteritis, characterized by diarrhea, abdominal cramps, and vomiting, is often caused by ingestion of contaminated food or water and is frequently associated with pathogenic Escherichia coli strains. These microbes exploit two principal mechanisms to inflict disease.Shiga toxin–producing E. coli, also referred to as STEC—notably O157:H7—release Shiga toxins that target ribosomes, blocking protein synthesis. The B subunit of the toxin binds the host glycolipid receptor...
01:19Translocation of Proteins into the Mitochondria
Mitochondrial precursors are translocated to the internal subcompartments via independent mechanisms involving distinct protein machineries called translocases.
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...