Membrane type 4 matrix metalloproteinase (MMP17) has tumor necrosis factor-α convertase activity but does not activate pro-MMP2
Membrane type 4 matrix metalloproteinase (MMP17) has tumor necrosis factor-α convertase activity but does not activate pro-MMP2
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DOI：
10.1074/jbc.275.19.14046
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发表时间：
2000-05-12
影响因子：
4.8
通讯作者：
Murphy, G
中科院分区：
文献类型：
--
作者：
English, WR;Puente, XS;Murphy, G
膜型4基质金属蛋白酶（MT4-MMP）与其他MT-MMP的序列同源性最低，表明该蛋白具有独特的功能。我们已经分离出一个完整的cDNA对应的小鼠同源物，其中包括信号肽和一个完整的前域，功能，缺乏从最初分离的人的形式。在COS-7细胞中表达的小鼠MT4-MMP（mMT4-MMP）位于细胞表面，但不显示激活pro-MMP 2的能力。前催化结构域在大肠杆菌中表达为不溶性内含物，重折叠后恢复活性酶。分离的催化结构域对通常用于MMP酶测定的合成肽的活性可被TIMP 1、TIMP-2和TIMP-3抑制。重组mMT4-MMP催化结构域也不能激活pro-MMP 2，并且除了纤维蛋白原和纤维蛋白外，在水解细胞外基质组分方面非常差。mMT4-MMP能够有效地水解由前肿瘤坏死因子α（TNF α）切割位点组成的肽（谷胱甘肽S-转移酶-proTNF α融合蛋白），并且发现当在COS-7细胞中共转染时释放pro-TNF α。通过蛋白质印迹法在单核细胞/巨噬细胞系中检测到MT4-MMP，其与其纤维蛋白溶解和TNF α转化活性结合表明在炎症中的作用。
Membrane type 4 matrix metalloproteinase (MT4-MMP) shows the least sequence homology to the other MT-MMPs, suggesting a distinct function for this protein. We have isolated a complete cDNA corresponding to the mouse homologue which includes the signal peptide and a complete pro-domain, features that were lacking from the human form originally isolated. Mouse MT4-MMP (mMT4-MMP) expressed in COS-7 cells is located at the cell surface but does not show ability to activate pro-MMP2. The pro-catalytic domain was expressed in Escherichia coli as insoluble inclusions and active enzyme recovered after refolding. Activity of the isolated catalytic domain against synthetic peptides commonly used for MMP enzyme assays could be inhibited by TIMP1, -2, and -3. The recombinant mMT4-MMP catalytic domain was also unable to activate pro-MMP2 and was very poor at hydrolyzing components of the extracellular matrix with the exception of fibrinogen and fibrin. mMT4-MMP was able to hydrolyze efficiently a peptide consisting of the pro-tumor necrosis factor alpha (TNF alpha) cleavage site, a glutathione S-transferase-proTNF alpha fusion protein, and was found to shed pro-TNF alpha when co-transfected in COS-7 cells. MT4-MMP was detected by Western blot in monocyte/macrophage cell lines which in combination with its fibrinolytic and TNF alpha-converting activity suggests a role in inflammation.