Intracellular zinc distribution and transport in C6 rat glioma cells
Intracellular zinc distribution and transport in C6 rat glioma cells
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DOI：
10.1016/s0006-291x(02)02017-x
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发表时间：
2002-08-30
影响因子：
3.1
通讯作者：
Beyersmann, D
中科院分区：
文献类型：
--
作者：
Haase, H;Beyersmann, D
在哺乳动物细胞中，锌的细胞内可用性影响许多关键过程。它的分布以前已经用几种荧光探针可视化，但尚不清楚这些探针如何在细胞内区室化。在这里，我们表明，在C6细胞的锌特异性探针锌是均匀分布的。因此，细胞核中显著较低的荧光水平和点状囊泡染色是锌浓度的真实的差异。通过释放细胞内蛋白质结合的锌与巯基反应性N-乙基马来酰亚胺（NEM）的稳定状态的化学扰动导致锌的钒酸盐敏感运输出细胞核并进入锌小体。如果用组氨酸反应性焦碳酸二乙酯进行锌释放，与用NEM处理相比，螯合减少，表明组氨酸在膜锌转运蛋白中的重要性。调节锌稳态的另一个主要因素是离子输出。如通过原子吸收光谱法测定的，高达50%的细胞锌通过对镧离子敏感的机制输出。我们得出结论，不同浓度的不稳定锌存在于不同的细胞室，这是由出口和细胞内转运锌。(C)2002 Elsevier Science（美国）。All rights reserved.
In mammalian cells, the intracellular availability of zinc influences numerous crucial processes. Its distribution has previously been visualized with several fluorescent probes, but it was unclear how these probes are compartmentalized within the cell. Here, we show that in C6 cells the zinc-specific probe Zinquin is evenly distributed. Thus, the significantly lower level of fluorescence in the nucleus and a punctuate vesicular staining are real differences in the concentrations of zinc. Chemical perturbation of the steady state by releasing intracellular protein-bound zinc with the sulfhydryl-reactive N-ethylmaleimide (NEM) resulted in a vanadate sensitive transport of zinc out of the nucleus and into zincosomes. If the,zinc-release was performed with the histidine-reactive diethylpyrocarbonate, sequestration was reduced compared to treatment with NEM, indicating the importance of histidine within membrane zinc transporters. Another major factor regulating the zinc homeostasis is ion export. As determined by atomic absorption spectroscopy, up to 50% of the cellular zinc was exported by a mechanism sensitive to lanthanum ions. We conclude that different concentrations of labile zinc exist in different cellular compartments, which are maintained by export and intracellular transport of zinc. (C) 2002 Elsevier Science (USA). All rights reserved.