Cl-/H+ 反载体 ClC-7 是 lysosomes 中的主要化物浸透通道
Austin R Graves1, Patricia K Curran, Carolyn L Smith
1Membrane Transport Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Drive, Building 35, MSC 3701, Bethesda, Maryland 20892, USA.
Nature
|May 2, 2008
概括
通道7 (ClC-7) 作为一种重要的Cl-/H+抗载体,促进了溶酶体的酸化. 这项研究确定了ClC-7是溶酶体中主要的离子载体,对细胞降解和功能至关重要.
科学领域:
- 细胞生物学 细胞生物学
- 分子生物学分子生物学
- 生理学 生理学 生理学
背景情况:
- 溶解体是宏分子降解的关键器官,需要酸性光pH来进行酶活性.
- 酸化主要由V型质子ATPase驱动,但平行离子通路对于高效的质子传输至关重要.
- lysosomal 阴离子载体的分子身份一直是难以捉摸的,阻碍了对 lysosomal 功能的理解.
研究的目的:
- 为了确定 lysosomes 中必不可少的离子载体的分子身份.
- 确定ClC-7 (化物通道7) 在溶酶体生物学和酸化中的功能.
- 阐明ClC-7在细胞降解途径中的作用.
主要方法:
- 异质表达和ClC-7的功能特征.
- 溶酶体膜阳离子输送试验.
- 短干扰RNA (siRNA) 的介导下降了ClC-7的表达.
- 在ClC-7淘汰细胞中对 lysosomal 酸化的体内评估.
主要成果:
- 在 lysosomes 中表现出 Cl-/H+ 反载体活性,具有 CLC 载体的特征.
- 确定了ClC-7作为溶酶体膜中占主导地位的阴离子载体.
- 表明ClC-7的淘汰显著降低了 lysosomal Cl-/H+抗载体活性,并在体内损害了 lysosomal 酸化.
结论:
- ClC-7 是一个Cl-/H+反载体,也是溶酶体中主要的Cl-通透性通路.
- ClC-7在维持 lysosomal 酸度方面起着至关重要的作用,这对 lysosomal 功能至关重要.
- 丧失ClC-7功能对溶解体生物学和相关疾病,如骨质疏松症,有重大影响.
相关概念视频
Delivery Pathways to the Lysosome
Eukaryotic cells use different mechanisms to eliminate toxic waste obsolete and worn-out substances. Lysosomes play a pivotal role in this, and hence, these substances are carried to the lysosome from other parts of the cell and extracellular space through different pathways. The most elaborately studied pathways to the lysosome are the endocytic pathways.
Endocytosis
In endocytosis, the cell membrane takes up macromolecules and particles from the surrounding medium. Clathrin-mediated...
Endocytosis
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Lysosomal Hydrolases
Lysosomes are the site for the degradation of macromolecules and biological polymers released during membrane trafficking events such as secretory, endocytic, autophagic, and phagocytic pathways. The membrane-enclosed area of the lysosome, called the lumen, contains hydrolytic enzymes active in an acidic environment. These acid hydrolases are functional at a pH between 4.5 and 5 and are involved in cellular processes such as cell signaling, energy metabolism, restoration of the plasma membrane,...
Clathrin Coated Vesicles
Clathrin-coated vesicles use endocytosis to transport receptors and lysosomal hydrolases from the Golgi to the lysosome in the late secretory pathway. Clathrin-mediated endocytosis was the first described endocytic process, and Clathrin-coated vesicles remain one of the most well-studied transport vesicles. The molecular machinery that generates clathrin-coated vesicles comprises over 50 proteins that precisely coordinate vesicle formation. Cell surface receptors concentrated in indented sites...
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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...
Reabsorption and Secretion in the PCT
The Proximal Convoluted Tubule, or PCT, plays a pivotal role in the body's filtration system. They are primarily responsible for reabsorbing solutes and water from the filtered fluid produced by the glomeruli. Most of the filtered water, ions, and organic solutes such as glucose and amino acids are reabsorbed by the PCT.
Transport mechanisms involving sodium ions (Na+) contribute significantly to solute reabsorption. These mechanisms include symport and antiport processes.
A key example is the...
Transport mechanisms involving sodium ions (Na+) contribute significantly to solute reabsorption. These mechanisms include symport and antiport processes.
A key example is the...
Reabsorption and Secretion in the Loop of Henle
The thick ascending limb of the nephron loop has Na+–K+–2Cl− symporters in the apical membranes of its cells. These symporters simultaneously reclaim one sodium ion, one potassium ion, and two chloride ions from the tubular fluid. Sodium ions are actively transported into the interstitial fluid at the base and sides of the cell, diffusing into the vasa recta. Chloride ions move through leakage channels in the basolateral membrane into the interstitial fluid and then into the vasa recta.


