线粒体透性:ADP/ATP转位器的双重作用?
1Department of Biochemistry, University of Bristol, Bristol BS8 1TD, UK. a.halestrap@bristol.ac.uk
Nature
|August 31, 2004
概括
腺核酸转位酶 (ANT) 可能不必形成线粒体透性过渡孔 (mtPTP). ANT-knockout小鼠肝脏线粒体仍然表现出mtPTP活性,这表明ANT对于细胞死亡是不可或缺的.
科学领域:
- 线粒体生物学 线粒体生物学
- 细胞死亡途径的细胞死亡途径.
- 生物化学 生物化学
背景情况:
- ADP/ATP转位器 (ANT) 便于通过线粒体内膜运输ADP/ATP.
- T还参与形成线粒体透性过渡孔 (mtPTP),这是亡的关键媒介.
- 一种被广泛接受的模型假定ANTT在mtPTP形成中的重要作用.
研究的目的:
- 调查ANTT在线粒体透性过渡孔 (mtPTP) 的形成中的作用.
- 为了确定ANT是否对mtPTP相关的细胞死亡至关重要.
主要方法:
- 使用了来自ANT-knockout小鼠 (基因失活的ANT) 的肝脏线粒体.
- 评估了这些淘汰线粒体中的线粒体透性过渡孔 (mtPTP) 活性.
主要成果:
- 来自ANT淘汰赛小鼠的线粒体保留了显著的mtPTP活性.
- 这表明,对于mtPTP的形成或功能来说,ANT并不严格要求.
- 这些发现挑战了ANT在mtPTP相关的亡中的既定作用.
结论:
- 腺核酸转位酶 (ANT) 是 mtPTP 的一个非必不可少的组成部分.
- 对于与mtPTP相关的细胞死亡,ANT可能是不必要的.
- 这些结果需要重新评估ANTT在肝脏代谢和细胞死亡中的功能.
相关概念视频
ATP Driven Pumps I: An Overview
ATP-driven pumps, also known as transport ATPases, are integral membrane proteins. They have binding sites for ATP located on the membrane's cytosolic side and the ion-conducting domain in the transmembrane region. These pumps use the free energy released from ATP hydrolysis to move the solutes across cell membranes against an electrochemical gradient.
There are four main types of ATP-driven pumps - P-type, V-type, F-type, and ABC transporter. All these pumps are of varying complexities and are...
There are four main types of ATP-driven pumps - P-type, V-type, F-type, and ABC transporter. All these pumps are of varying complexities and are...
ATP Synthase: Mechanism
In animals, the mitochondrial F1F0 ATP synthase is the key protein that synthesizes ATP molecules through a complex catalytic mechanism. While the nuclear genome encodes the majority of ATP synthase subunits, the mitochondrial genome encodes some of the enzyme's most critical components. The formation of this multi-subunit enzyme is a complex multi-step process regulated at the level of transcription, translation, and assembly. Defects in one or more of these steps can result in decreased ATP...
ATP Synthase: Structure
ATP synthase or ATPase is among the most conserved proteins found in bacteria, mammals, and plants. This enzyme can catalyze a forward reaction in response to the electrochemical gradient, producing ATP from ADP and inorganic phosphate. ATP synthase can also work in a reverse direction by hydrolyzing ATP and generating an electrochemical gradient. Different forms of ATP synthases have evolved special features to meet the specific demands of the cell. Based on their specific feature, ATP...
The ADP/ATP Carrier Protein
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...
ATP Driven Pumps II: P-type Pumps
The P-type pumps are a large family of integral membrane transporter ATPases. They are divided into five major types based on substrate specificity, from I to V.
A typical P-type pump has three cytosolic domains: nucleotide-binding (N), phosphorylation (P), and activator (A) domains. These domains are connected to the membrane-spanning helices by short amino acid segments. ATP hydrolysis and covalent phosphoenzyme intermediate formation are crucial parts of the catalytic cycle. At the highly...
A typical P-type pump has three cytosolic domains: nucleotide-binding (N), phosphorylation (P), and activator (A) domains. These domains are connected to the membrane-spanning helices by short amino acid segments. ATP hydrolysis and covalent phosphoenzyme intermediate formation are crucial parts of the catalytic cycle. At the highly...
Membrane Asymmetry Regulating Transporters
Enzymes like flippase, floppase, and scramblase transfer phospholipids from one layer to another in the membrane, thereby affecting membrane asymmetry.
Flippase
Eukaryotic flippases are type-IV P-type ATPases or P4-ATPases belonging to P-type ATPase family proteins that are membrane-bound pumps involved in the ATP-mediated transport of ions and molecules across the membrane. Flippases flip specific phospholipids from the outer to the inner leaflet of a membrane. All P4-ATPases have one...
Flippase
Eukaryotic flippases are type-IV P-type ATPases or P4-ATPases belonging to P-type ATPase family proteins that are membrane-bound pumps involved in the ATP-mediated transport of ions and molecules across the membrane. Flippases flip specific phospholipids from the outer to the inner leaflet of a membrane. All P4-ATPases have one...


