イカッパBキナーゼ2によるSNAP-23のリン酸化は,マスト細胞のデグラヌレーションを調節する
1Laboratory of Genetics, The Salk Institute, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
Cell
|August 12, 2008
まとめ
マスト細胞のイカッパBキナーゼ (IKK) 2は,アレルギー反応に不可欠です. 直接SNAP-23をリン酸化し,NF-kBとは無関係にIgE媒介のデグラヌレーションとアナフィラキシーを誘導する.
科学分野:
- 免疫学 免疫学とは
- 細胞生物学 細胞生物学
背景:
- マスト細胞は,アレルギー性疾患において重要な役割を果たします.
- IgE受容体 (FcεRI) のクロスリンクは,マスト細胞のデグラヌレーションと炎症を誘発する.
- IgE依存エクソサイトーシスの規制メカニズムは完全に理解されていません.
研究 の 目的:
- マスト細胞のデグラヌレーションとIgE媒介のアレルギー反応におけるIkappaBキナーゼ (IKK) 2の役割を調査する.
- マスト細胞におけるIKK2によって調節される下流の標的と経路を解明する.
主な方法:
- IKK2欠乏性マスト細胞をインビトロデグラヌレーション試験に利用した.
- FcεRI刺激によるSNAP-23のリン酸化状態を調査した.
- 機能的救済を評価するために,SNAP-23変異体の子宮外発現を用いた.
主要な成果:
- IKK2は,IgE媒介のアナフィラキシー in vivoおよびデグラヌレーション in vitroにおいて不可欠である.
- IKK2は,NF-κBから独立して,SNAP-23を直接リン酸化し,SNAREの重要なタンパク質である.
- IKK2によるSNAP-23のリン酸化は,IgE媒介のデグラヌレーションに不可欠である.
結論:
- IKK2は,マスト細胞のデグラヌレーションとアレルギー反応において中心的な役割を果たします.
- IKK2媒介によるSNAP-23のリン酸化は,IgE依存エクソサイトーシスの重要なステップです.
- IKK2は,NF-κB依存型サイトカインの放出を通じて,後期アレルギー反応を調節し,その二重な役割を強調しています.
関連する概念動画
IP3/DAG Signaling Pathway
15.2K
Membrane lipids such as phosphatidylinositol (PI) are precursors for several membrane-bound and soluble second messengers. Specific kinases phosphorylate PI and produce phosphorylated inositol phospholipids. One such inositol phospholipids are the phosphatidylinositol-4,5 bisphosphate [PI(4,5)P2], present in the inner half of the lipid bilayer. Upon ligand binding, GPCR stimulates Gq proteins to turn on phospholipase Cꞵ. Activated phospholipase Cꞵ cleaves PI(4,5)P2 and...
15.2K
Amplifying Signals via Enzymatic Cascade
18.7K
When a ligand binds to a cell-surface receptor, the receptor's intracellular domain changes shape, which may either activate its enzyme function or allow its binding to other molecules. The initial signal is amplified by most signal transduction pathways. This means that a single ligand molecule can activate multiple molecules of a downstream target. Proteins that relay a signal are most commonly phosphorylated at one or more sites, activating or inactivating the protein. Kinases catalyze...
18.7K
Calmodulin-dependent Signaling
6.7K
Calmodulin (CaM) is a calcium-binding protein in eukaryotes that controls various calcium-regulated cellular processes. It has four calcium-binding sites that bind calcium to form the calcium-calmodulin ( Ca2+-CaM) complex. GPCR stimulation increases the calcium levels in the cells that bind to CaM and induces a conformational change.
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
6.7K
NF-κB-dependent Signaling Pathway
10.1K
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...
10.1K
The JAK-STAT Signaling Pathway
13.3K
Several cytokine receptors have tightly bound Janus kinase or JAK proteins attached at their cytosolic tail. Small signaling molecules such as cytokines, growth hormones, or prolactins bind to the cytokine receptors and initiate their dimerization. The dimerization brings the cytosolic JAKs together that trans-phosphorylate and activates each other. The activated JAKs now phosphorylate cytosolic tails of the cytokine receptors, which serve as binding sites for adaptor proteins such as SH2...
13.3K
Protein Kinases and Phosphatases
15.3K
Proteins undergo chemical modifications that trigger changes in the charge, structure, and conformation of the proteins. Phosphorylation, acetylation, glycosylation, nitrosylation, ubiquitination, lipidation, methylation, and proteolysis are various protein modifications that regulate protein activity. Such modifications are usually enzyme-driven.
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
15.3K


