メタボリズム S-ニトロシレーションは,肥満に関連した炎症とエンドプラズマ網膜機能障害を関連付けています
Ling Yang1, Ediz S Calay1, Jason Fan1
1Department of Genetics and Complex Diseases and Sabri Ülker Center, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA.
まとめ
肥満における炎症は,誘導性酸化窒素合成酵素 (iNOS) 活動を通じて,内プラズマ網膜 (ER) のストレス反応を損なう. これはERホメオスタシスとタンパク質機能を損なっており,肥満に関連する合併症に寄与します.
科学分野:
- 細胞生物学
- 分子生物学
- 代謝疾患
背景:
- 慢性的な炎症と内プラズマ網膜 (ER) のストレスは,様々な疾患に関連しています.
- 慢性疾患における開折タンパク質応答 (UPR) とERホメオスタシスに対する慢性炎症の調節作用は十分に理解されていません.
研究 の 目的:
- 慢性炎症が肥満におけるUPRとERホメオスタシスを調節するメカニズムを調査する.
- 肥満中のERストレスにおける誘導性酸化窒素合成酵素 (iNOS) とIRE1αの役割を決定する.
主な方法:
- マウスにおける肥満の遺伝的 (ob/ob) および食事的 (高脂肪食) モデルを使用した.
- IRE1α S- ニトロシル化とXBP1スプライシングに対するiNOSの影響を評価した.
- 肝臓特異的なIRE1α欠乏症のマウスとニトロシル化に抵抗するIRE1αの変種を使用した.
主要な成果:
- 肥満のマウスのiNOS活性が増加すると,IRE1αのS- ニトロシル化が起こり,その機能が低下した.
- これにより,XBP1のスプライシング活性が低下し,ERホメオスタシスが損なわれた.
- 肥満のマウスでは,ニトロシル化抵抗性IRE1αを回復させることで,XBP1のスプライシングとグルコース代謝が改善された.
結論:
- 炎症経路,特にINOS媒介のIRE1αのS- ニトロシル化が,肥満におけるUPR機能を破壊する.
- このメカニズムは,欠陥のあるIRE1α活性,ER機能の障害,および肥満における持続的なERストレスに寄与する.
- この経路をターゲットにすることで 肥満に関連した代謝機能障害の治療策を提供することができます
関連する概念動画
Protein Modifications in the RER
7.6K
Modification of secretory and transmembrane proteins entering the rough ER begins in the ER lumen. These modifications aid in protein folding and stabilize the acquired tertiary structure. Protein modifications in the rough ER co-occur at different stages of protein folding.
Broadly, these modifications can be categorized into four main categories — glycosylation, formation of disulfide bonds, assembly of protein subunits, and specific proteolytic cleavages like removal of signal...
Broadly, these modifications can be categorized into four main categories — glycosylation, formation of disulfide bonds, assembly of protein subunits, and specific proteolytic cleavages like removal of signal...
7.6K
Regulation of the Unfolded Protein Response
3.2K
Inositol-requiring kinase one or IRE1 is the most conserved eukaryotic unfolded protein response (UPR) receptor. It is a type I transmembrane protein kinase receptor with a distinctive site-specific RNase activity. As the binding mechanics of the misfolded proteins with the N-terminal domain of IRE-1 are unclear, three binding models — direct, indirect, and allosteric -- are proposed for receptor activation. Nevertheless, it is known that once a misfolded protein associates with IRE1, it...
3.2K
Role of ER in the Secretory Pathway
7.8K
Eukaryotic cells have a special pathway that enables communication between various intracellular membrane-bound compartments and also with the extracellular environment. This pathway is termed as the secretory pathway.
Components of the secretory pathway
About a third of proteins synthesized in the cell are sorted via the secretory route. They shuffle between different compartments in membrane-bound vesicles until they reach their final destination. The main intracellular compartments involved...
Components of the secretory pathway
About a third of proteins synthesized in the cell are sorted via the secretory route. They shuffle between different compartments in membrane-bound vesicles until they reach their final destination. The main intracellular compartments involved...
7.8K
NF-κB-dependent Signaling Pathway
10.4K
The transcription factor NF-κB was discovered in 1986 in the lab of Nobel laureate Professor David Baltimore, for its interaction with the immunoglobulin light chain enhancer in B-cells. After more than three decades of study, it is now evident that NF-κB regulates the expression of over 100 genes. Most of these genes play an essential role in the innate and adaptive immune responses as well as the inflammatory responses of animals.
NF-κB-dependent Signaling Mechanism
The...
NF-κB-dependent Signaling Mechanism
The...
10.4K
Protein Folding Quality Check in the RER
5.7K
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...
5.7K
The Unfolded Protein Response
7.0K
The ER is the hub of protein synthesis in a cell. It has robust systems to quality control protein folding and also for degradation of terminally misfolded proteins. Under normal conditions, a small proportion of misfolded proteins that cannot be salvaged need to be transported to the cytoplasm by the ER-associated degradation or ERAD pathways. However, if the ERAD cannot handle the misfolded proteins, the cell activates the unfolded protein response or UPR to adjust the protein folding...
7.0K


