[转移贴]-PNAS:发现影响流感病毒组装和释放宿主蛋白—F1F0-A...

rojjer

原帖由ipsvirus发表于16/3/2012 19:27
近日，流感大牛美国威思康星-麦迪逊大学病毒学教授Yoshihiro Kawaoka出新文章了，研究发现人体细胞中一种蛋白质F1F0-ATPase对流感病毒在人体内增殖发挥着重要作用。这一发现将有助于研发出治疗各种类型流感的新药物。相应研究成果在线发表在新一期《美国国家科学院院刊》上。文章的第一作者是Kawaoka教授在东京大学的实验室人员。

了解病毒在宿主细胞增殖过程中有哪些宿主分子参与，帮助人们对病毒的生活周期进行了解，从而有利于开发抗病毒药物。 Kawaoka教授等研究人员对与流感病毒非结构蛋白NS2相互作用的宿主分子做质谱分析，结果发现F1F0-ATPase的β 亚基与NS2蛋白亲和力很高，通过siRNA对β 亚基knock-down后发现抑制了病毒的增殖。进一步的机制研究发现流感病毒粒子的组装和释放需要细胞质膜上的F1F0-ATPase的ATP酶活性。该研究使人们对流感病毒的生活周期又有了进一步的了解。

研究小组指出：流感病毒变异后，会出现耐药性，但是如果以人的蛋白质为靶子开发药物，就不会出现耐药性问题。而F1F0-ATPase能否成为抗病毒药物靶标需要进一步研究。


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rojjer

F1Fo-ATPase, F-type proton-translocating ATPase, at the plasma membrane is critical for efficient influenza virus budding

Gorai, Takeo; Goto, Hideo; Noda, Takeshi; Watanabe, Tokiko; Kozuka-Hata, Hiroko; Oyama, Masaaki; Takano, Ryo; Neumann, Gabriele; Watanabe, Shinji; Kawaoka, Yoshihiro

The identification of host factors involved in virus replication is important to understand virus life cycles better. Accordingly, we sought host factors that interact with the influenza viral nonstructural protein 2 by using coimmunoprecipitation followed by mass spectrometry. Among proteins associating with nonstructural protein 2, we focused on the β subunit of the F1Fo-ATPase, which received a high probability score in our mass spectrometry analysis. The siRNA-mediated down-regulation of the β subunit of the F1Fo-ATPase reduced influenza virion formation and virus growth in cell culture. We further found that efficient influenza virion formation requires the ATPase activity of F1Fo-ATPase and that plasma membrane-associated, but not mitochondrial, F1Fo-ATPase is important for influenza virion formation and budding. Hence, our data identify plasma membrane-associated F1Fo-ATPase as a critical host factor for efficient influenza virus replication.

原文链接http://www.pnas.org/content/early/2012/03/01/1114728109.abstract

rojjer

极乐净土：
补充点信息：

ATPases are a class of enzymes that catalyze the decomposition of adenosine triphosphate (ATP) into adenosine diphosphate (ADP) and a free phosphate ion. This dephosphorylation reaction releases energy, which the enzyme (in most cases) harnesses to drive other chemical reactions that would not otherwise occur. This process is widely used in all known forms of life.

Some such enzymes are integral membrane proteins (anchored within biological membranes), and move solutes across the membrane, typically against their concentration gradient. These are called transmembrane ATPases.
  Na+/K+ATPase
Transmembrane ATPases import many of the metabolites necessary for cell metabolism and export toxins, wastes, and solutes that can hinder cellular processes. An important example is the sodium-potassium exchanger (or Na+/K+ATPase), which establishes the ionic concentration balance that maintains the cell potential. Another example is the hydrogen potassium ATPase (H+/K+ATPase or gastric proton pump) that acidifies the contents of the stomach.

Besides exchangers, other categories of transmembrane ATPase include co-transporters and pumps (however, some exchangers are also pumps). Some of these, like the Na+/K+ATPase, cause a net flow of charge, but others do not. These are called "electrogenic" and "nonelectrogenic" transporters, respectively.
Mechanism

The coupling between ATP hydrolysis and transport is more or less a strict chemical reaction, in which a fixed number of solute molecules are transported for each ATP molecule that is hydrolyzed; for example, 3 Na+ ions out of the cell and 2 K+ ions inward per ATP hydrolyzed, for the Na+/K+ exchanger.

Transmembrane ATPases harness the chemical potential energy of ATP, because they perform mechanical work: they transport solutes in a direction opposite to their thermodynamically preferred direction of movement—that is, from the side of the membrane where they are in low concentration to the side where they are in high concentration. This process is considered active transport.

For example, the blocking of the vesicular H+-ATPAses would increase the pH inside vesicles and decrease the pH of the cytoplasm.

Transmembrane ATP synthases

Main article: ATP synthase

The ATP synthase of mitochondria and chloroplasts is an anabolic enzyme that harnesses the energy of a transmembrane proton gradient as an energy source for adding an inorganic phosphate group to a molecule of adenosine diphosphate (ADP) to form a molecule of adenosine triphosphate (ATP).

This enzyme works when a proton moves down the concentration gradient, giving the enzyme a spinning motion. This unique spinning motion bonds ADP and P together to create ATP.

ATP synthase can also function in reverse, that is, use energy released by ATP hydrolysis to pump protons against their thermodynamic gradient.

Classification
There are different types of ATPases, which can differ in function (ATP synthesis and/or hydrolysis), structure (F-, V- and A-ATPases contain rotary motors) and in the type of ions they transport.
F-ATPases (F1FO-ATPases) in mitochondria, chloroplasts and bacterial plasma membranes are the prime producers of ATP, using the proton gradient generated by oxidative phosphorylation (mitochondria) or photosynthesis (chloroplasts).
V-ATPases (V1VO-ATPases) are primarily found in eukaryotic vacuoles, catalysing ATP hydrolysis to transport solutes and lower pH in organelles like proton pump of lysosome.
A-ATPases (A1AO-ATPases) are found in Archaea and function like F-ATPases
P-ATPases (E1E2-ATPases) are found in bacteria, fungi and in eukaryotic plasma membranes and organelles, and function to transport a variety of different ions across membranes.
E-ATPases are cell-surface enzymes that hydrolyse a range of NTPs, including extracellular ATP.