Sato H, Takino T, Kinoshita T, Imai K, Okada Y, Stetler Stevenson W G, Seiki M
Department of Molecular Virology and Oncology, Cancer Research Institute, Kanazawa University, Japan.
FEBS Lett. 1996 May 6;385(3):238-40. doi: 10.1016/0014-5793(96)00389-4.
Gelatinase A is secreted as a proenzyme (progelatinase A) which is activated and bound on the surface of tumor and normal cells. We have reported that the expression of a membrane-type-1-matrix metalloproteinase (MT1-MMP) induces activation of progelatinase A. Here we demonstrate that the expression of MT1-MMP in COS-1 cells induces cell-surface binding of progelatinase A which is consequently processed to an intermediate form. Processing from the intermediate to the fully active form is dependent on the gelatinase A concentration. These results suggest that the cell-surface binding concentrates the gelatinase A intermediate form locally to allow autoproteolytic processing to the fully active form.
明胶酶A以酶原形式（前明胶酶A）分泌，该酶原在肿瘤细胞和正常细胞表面被激活并结合。我们曾报道，膜型1基质金属蛋白酶（MT1-MMP）的表达可诱导前明胶酶A的激活。在此我们证明，MT1-MMP在COS-1细胞中的表达可诱导前明胶酶A在细胞表面的结合，进而使其加工成中间形式。从中间形式加工成完全活性形式取决于明胶酶A的浓度。这些结果表明，细胞表面结合将明胶酶A中间形式局部浓缩，从而允许其自动蛋白水解加工成完全活性形式。
