Na+チャネル内のリン酸化部位は,タンパク質キナーゼCによる調節に必要なものです
J W West1, R Numann, B J Murphy
1Department of Pharmacology, University of Washington, Seattle 98195.
まとめ
タンパク質キナーゼCの活性化は,セリン1506.6をリン酸化することによって,電圧ゲートされたナトリウムチャネルを調節する. このリン酸化部位は,ナトリウムチャネル活性と刺激性細胞におけるアクションポテンシャル生成の調節に極めて重要です.
科学分野:
- 神経科学は神経科学である.
- 分子生物学は分子生物学である.
- 細胞生理学 細胞生理学
背景:
- ボルテージゲートナトリウムチャネルは,興奮性の細胞におけるアクションポテンシャル生成に不可欠である.
- タンパク質キナーゼC (PKC) は,ナトリウムチャネル機能を調節することが知られている.
研究 の 目的:
- PKCが電圧誘導ナトリウムチャネルを調節する特定の分子機構を調査する.
- ナトリウムチャネルにPKC媒介による影響を及ぼす主要なリン酸化部位を特定する.
主な方法:
- サイト・ディレクテッド・ミュータゲネシスにより,セリン1506変異性ナトリウムチャネルが作られる.
- 電気生理学的記録 (例えば,パッチクランプ) で,チャネル機能を評価する.
- リン酸化状態を確認するために,ウエスタン・ブロッティングまたは他の生化学分析を行う.
主要な成果:
- ドメインIIIとドメインIVの間の細胞内ループにおけるセリン1506のリン酸化は,PKC誘発によるナトリウムチャネル不活性化の減速のために必要である.
- セリン1506のリン酸化が欠けている変異チャネルは,PKCの活性化時に変化した無活性化または減少したピーク電流を示さない.
- 特定されたリン酸化部位は,異なるナトリウムチャネルサブタイプにわたって保存されます.
結論:
- セリン1506のリン酸化は,電圧誘導ナトリウムチャネル機能の重要な調節メカニズムです.
- PKCによるこのリン酸化イベントは,神経刺激性を調節する上で重要な役割を果たします.
- この部位をターゲットにすると,変化した電気的活動を含む状態のための治療戦略を提供することができる.
さらに関連する動画
07:38Functional Characterization of Na+/H+ Exchangers of Intracellular Compartments Using Proton-killing Selection to Express Them at the Plasma Membrane
Published on: March 30, 2015
12:26Functional Site-Directed Fluorometry in Native Cells to Study Skeletal Muscle Excitability
Published on: June 2, 2023
関連する概念動画
Stomach pH Regulation
The human body carefully regulates the internal pH of different organs to maintain homeostasis. For example, while the blood plasma maintains a neutral pH of 7, the stomach lumen has an acidic pH of 1.5 - 3.5. The low pH of stomach lumen helps kill pathogens in the food and break down complex food molecules.
The acid-secreting gastric mucosal epithelial cells (parietal cells) lining the stomach lumen maintain the low pH in the lumen. Numerous ion transporters and channels on these parietal...
The acid-secreting gastric mucosal epithelial cells (parietal cells) lining the stomach lumen maintain the low pH in the lumen. Numerous ion transporters and channels on these parietal...
pH Regulation in Cells
pH plays a critical role in maintaining normal cellular activities. It helps maintain the structure and function of various proteins, dictates the charge on cellular membranes, and is crucial for metabolic reactions inside the cell. Moreover, cells use the energy from the proton motive force to generate ATP.
Cytosolic pH
Under physiological conditions, the cytosolic pH is slightly more acidic than the extracellular pH. However, cells must prevent further acidification of their cytosol to...
Cytosolic pH
Under physiological conditions, the cytosolic pH is slightly more acidic than the extracellular pH. However, cells must prevent further acidification of their cytosol to...
pH Homeostasis
Acid-base homeostasis is essential for maintaining normal physiological activities in humans. The pH of various body fluids is strictly regulated because it is critical for the optimal activity of enzymes involved in metabolic reactions. Enzymes are basically proteins, so, any significant change in pH can affect their structure and activity. In humans, pH is regulated using three primary mechanisms— chemical buffer systems, respiratory regulation, and renal regulation.
Respiratory Regulation of...
Respiratory Regulation of...
Renal Regulation of Acid-Base Balance
Metabolic reactions in the body produce nonvolatile acids, such as sulfuric acid, which generate an acid load of approximately 1 mEq of H+ per kilogram of body weight daily. Excreting H+ in the urine is essential to balance this acid load.
In the kidneys, cells within the proximal convoluted tubules (PCT) and the collecting ducts secrete hydrogen ions (H+) into the tubular fluid. Specifically, in the PCT, Na+/H+ antiporters secrete H+ while reabsorbing Na+.
However, the intercalated cells in...
In the kidneys, cells within the proximal convoluted tubules (PCT) and the collecting ducts secrete hydrogen ions (H+) into the tubular fluid. Specifically, in the PCT, Na+/H+ antiporters secrete H+ while reabsorbing Na+.
However, the intercalated cells in...
Amino Acid Catabolism
Microorganisms rely on proteins as an essential carbon and energy source, particularly in environments with limited polysaccharides or lipids. However, proteins are too large to cross the plasma membrane unaided, necessitating enzymatic degradation. Microbes secrete extracellular proteases and peptidases that hydrolyze proteins into peptides, which can then be transported across the membrane. Once inside the cell, intracellular proteases degrade these peptides into free amino acids, which...
Bacterial Protein Maturation
Bacterial protein maturation is a tightly regulated process that ensures newly synthesized polypeptides achieve correct functional conformations. This maturation involves a series of modifications, folding events, and quality control steps, often assisted by specialized chaperone proteins.N-Terminal ModificationsThe maturation of bacterial polypeptides begins cotranslationally as the polypeptide exits the ribosome. The first amino acid, N-formylmethionine (fMet), is typically modified at the...
