The N- and C-terminal fragments of ubiquitin are important for the antimicrobial activities
The N- and C-terminal fragments of ubiquitin are important for the antimicrobial activities
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DOI：
10.1096/fj.02-0699fje
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发表时间：
2003-02-01
期刊：
影响因子：
4.8
通讯作者：
Metz-Boutigue, MH
中科院分区：
文献类型：
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作者：
Kieffer, AE;Goumon, Y;Metz-Boutigue, MH
嗜铬细胞的分泌颗粒含有儿茶酚胺和几种来自嗜铬粒蛋白和脑啡肽原-A的抗菌肽。这些肽在胞吐作用后分泌到细胞外介质中。在这里，我们表明，泛素是储存在分泌嗜铬颗粒和释放到循环刺激嗜铬细胞。我们还表明，C-末端片段（残基65-76）的泛素显示，在微摩尔范围内，裂解抗真菌活性。使用共聚焦激光扫描显微镜和罗丹明标记的合成肽，我们可以证明，C-末端肽（残基65-76）能够穿过真菌的细胞壁和质膜，并在真菌中积累，而N-末端肽（残基1-34）停止在真菌壁水平。此外，这两种肽协同作用杀死丝状真菌。由于泛素的C-末端序列与钙调蛋白的相互作用，合成肽（残基65-76）在体外针对钙调蛋白依赖性钙调神经磷酸酶（一种对真菌生长至关重要的酶）进行了测试。发现该肽抑制钙调神经磷酸酶的磷酸酶活性。我们的数据显示了泛素C端衍生肽（65-76）的一个新特性，该特性可以与N端肽（1-34）一起用作新的有效抗真菌剂。
Secretory granules of chromaffin cells contain catecholamines and several antimicrobial peptides derived from chromogranins and proenkephalin-A. These peptides are secreted in the extracellular medium following exocytosis. Here, we show that ubiquitin is stored in secretory chromaffin granules and released into the circulation upon stimulation of chromaffin cells. We also show that the C-terminal fragment (residues 65-76) of ubiquitin displays, at the micromolar range, a lytic antifungal activity. Using confocal laser scan microscopy and rhodamine-labeled synthetic peptides, we could demonstrate that the C-terminal peptide (residues 65-76) is able to cross the cell wall and the plasma membrane of fungi and to accumulate in fungi, whereas the N-terminal peptide (residues 1-34) is stopped at the fungal wall level. Furthermore, these two peptides act synergistically to kill filamentous fungi. Because of the interaction of the C-terminal sequence of ubiquitin with calmodulin, the synthetic peptide (residues 65-76) was tested in vitro against calmodulin-dependent calcineurin, an enzyme crucial for fungal growth. This peptide was found to inhibit the phosphatase activity of calcineurin. Our data show a new property of ubiquitin C-terminal-derived peptide (65-76) that could be used with N-terminal peptide (1-34) as a new potent antifungal agent.