ヒトのミトコンドリアのピルバートベーカーの構造とメカニズム
Jiaming Liang1,2,3,4, Junhui Shi1,2,3,4, Ailong Song1,2,3,4
1Fudan University, Shanghai, China.
Nature
|March 18, 2025
まとめ
ミトコンドリアのピルバートキャリア (MPC) はピルバートをミトコンドリアに輸送する. Cryo-EM構造は,その交代的なアクセスメカニズムと,抑制剤UK5099がどのように結合し,薬の開発を支援することを明らかにします.
科学分野:
- 生物化学
- 構造生物学
- 細胞呼吸
背景:
- ミトコンドリアのピルバートキャリア (MPC) は,トリカルボキシル酸 (TCA) 循環を通じて細胞のエネルギー生産に不可欠なピルバートのミトコンドリアへの侵入を容易にする.
- MPCはミトコンドリア内膜に位置するヘテロジマー (MPC1とMPC2) で,ピルバートの唯一のゲートとして作用する.
研究 の 目的:
- 人間のMPC媒介によるピルベート輸送の構造的メカニズムを解明する.
- 阻害剤UK5099とMPCの結合を特徴づけるため
- MPCを標的とする薬の開発のための構造的基盤を提供すること.
主な方法:
- 人間のMPCの6つの冷凍電子顕微鏡構造が決定されました.
- 構造は,3つの異なる状態でMPCを捕捉した:膜間空間 (IMS) - 開いた,閉じた,およびマトリックス向き.
- 阻害剤UK5099と阻害ナノボディが特定の形状状態を捕まえるために使用されました.
主要な成果:
- Cryo-EMは,IMS開いた,遮断された,マトリックス向きの状態のMPC構造を明らかにし,偽C2対称性を示した.
- 状態間の移行には,固体運動とマトリックスサイドの形状の変化が含まれ,交互のアクセス輸送メカニズムを示しています.
- 阻害剤UK5099はマトリックス向きのポケットに結合し,MPCと広く相互作用する.
結論:
- この研究は,MPC輸送機構と基板転移に関する原子レベルの洞察を提供します.
- 構造データは,UK5099とMPCの相互作用を明らかにし,新しい阻害剤の設計を導く.
- これらの発見は,MPCによって調節される代謝経路を標的とした治療法の開発を容易にする.
さらに関連する動画
関連する概念動画
Pyruvate Oxidation
157.9K
After glycolysis, the charged pyruvate molecules enter the mitochondria via active transport and undergo three enzymatic reactions. These reactions ensure that pyruvate can enter the next metabolic pathway so that energy stored in the pyruvate molecules can be harnessed by the cells.
First, the enzyme pyruvate dehydrogenase removes the carboxyl group from pyruvate and releases it as carbon dioxide. The stripped molecule is then oxidized and releases electrons, which are then picked up by NAD+...
First, the enzyme pyruvate dehydrogenase removes the carboxyl group from pyruvate and releases it as carbon dioxide. The stripped molecule is then oxidized and releases electrons, which are then picked up by NAD+...
157.9K
The ADP/ATP Carrier Protein
3.1K
ADP/ATP carrier or AAC protein is the most abundant carrier protein in the inner mitochondrial membrane. It transports large quantities of ADP and ATP, equivalent to the average human body weight, every day. Among other transporters, ACC protein is one of the best-studied members of the mitochondrial carrier protein family. The ADP/ATP carrier protein comprises two transmembrane helices connected to a loop and a single alpha-helix on the matrix side. It switches between two conformational...
3.1K
Electron Transport Chain: Complex I and II
9.9K
The mitochondrial electron transport chain (ETC) is the main energy generation system in the eukaryotic cells. However, mitochondria also produce cytotoxic reactive oxygen species (ROS) due to the large electron flow during oxidative phosphorylation. While Complex I is one of the primary sources of superoxide radicals, ROS production by Complex II is uncommon and may only be observed in cancer cells with mutated complexes.
ROS generation is regulated and maintained at moderate levels necessary...
ROS generation is regulated and maintained at moderate levels necessary...
9.9K
Protein Transport into the Inner Mitochondrial Membrane
3.6K
Nuclear encoded mitochondrial precursors are imported to the inner membrane in a multistep process involving two separate translocons, TIM22 and TIM23. TIM23 is a cation-selective pore that remains closed by the N terminal segment of the protein. Negative charges on the TIM23 act as a receptor for the incoming precursor, pulling the positively charged matrix-targeting sequence for peptide insertion and translocation.
Transport of mitochondrial precursors across the TIM23 channel is driven by...
Transport of mitochondrial precursors across the TIM23 channel is driven by...
3.6K
The Inner Mitochondrial Membrane
3.2K
The inner mitochondrial membrane is the primary site of ATP synthesis. The inner membrane domain that forms a smooth layer adjacent to the outer membrane is called the inner boundary membrane. This domain contains membrane transporters that drive metabolites in and out of the mitochondria. In contrast, the inner membrane network that invaginates into the matrix space is called the cristae membrane. This domain accounts for principle mitochondrial function as it accommodates the protein...
3.2K
Electron Transport Chains
96.7K
The final stage of cellular respiration is oxidative phosphorylation that consists of two steps: the electron transport chain and chemiosmosis. The electron transport chain is a set of proteins found in the inner mitochondrial membrane in eukaryotic cells. Its primary function is to establish a proton gradient that can be used during chemiosmosis to produce ATP and generate electron carriers, such as NAD+ and FAD, that are used in glycolysis and the citric acid cycle.
The ETC is comprised of...
The ETC is comprised of...
96.7K


