The N-terminal ectodomain of Ninjurin1 liberated by MMP9 has chemotactic activity
The N-terminal ectodomain of Ninjurin1 liberated by MMP9 has chemotactic activity
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DOI：
10.1016/j.bbrc.2012.10.099
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发表时间：
2012-11-30
影响因子：
3.1
通讯作者：
Kim, Kyu-Won
中科院分区：
文献类型：
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作者：
Ahn, Bum Ju;Le, Hoang;Kim, Kyu-Won
忍者蛋白1是一种黏附分子，在炎症条件下促进白细胞的运输。然而，忍者1的翻译后修饰却鲜为人知。在此，我们定义了忍者1的蛋白水解性切割及其功能。HEK293T细胞过表达C端或N端标记的小鼠忍者1质粒，在裂解产物或条件培养液(CM)中产生额外的裂解形式的忍者1。针对忍者1的N-末端或C-末端的两种定制的抗忍者1抗体，抗体(1-15)或抗体(139-152)显示，在小鼠肝和肾的裂解物中存在其脱落片段。此外，基质金属蛋白酶(MMP9)参与了忍者1在Leu(56)和Leu(57)之间的切割。有趣的是，可溶的N端忍者1片段与已知的趋化因子具有结构上的相似性。事实上，从HEK293T细胞中获得的过表达GFP-mNins1质粒的CM在跨孔实验中能够吸引Raw264.7细胞。综上所述，我们认为小鼠忍者1的N端胞外区可能是一种化学诱导剂，被MMP9切割。(C)2012 Elsevier Inc.保留所有权利。
Ninjurin1 is known as an adhesion molecule promoting leukocyte trafficking under inflammatory conditions. However, the posttranslational modifications of Ninjurin1 are poorly understood. Herein, we defined the proteolytic cleavage of Ninjurin1 and its functions. HEK293T cells overexpressing the C- or N-terminus tagging mouse Ninjurin1 plasmid produced additional cleaved forms of Ninjurin1 in the lysates or conditioned media (CM). Two custom-made anti-Ninjurin1 antibodies, Ab(1-15) or Ab(139-152), specific to the N- or C-terminal regions of Ninjurin1 revealed the presence of its shedding fragments in the mouse liver and kidney lysates. Furthermore, Matrix Metalloproteinase (MMP) 9 was responsible for Ninjurin1 cleavage between Leu(56) and Leu(57). Interestingly, the soluble N-terminal Ninjurin1 fragment has structural similarity with well-known chemokines. Indeed, the CM from HEK293T cells overexpressing the GFP-mNinj1 plasmid was able to attract Raw264.7 cells in trans-well assay. Collectively, we suggest that the N-terminal ectodomain of mouse Ninjurin1, which may act as a chemoattractant, is cleaved by MMP9. (C) 2012 Elsevier Inc. All rights reserved.