Evidence for a direct interaction between the tumor suppressor serpin, maspin, and types I and III collagen
Evidence for a direct interaction between the tumor suppressor serpin, maspin, and types I and III collagen
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DOI：
10.1074/jbc.m110992200
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发表时间：
2002-03-29
影响因子：
4.8
通讯作者：
Worrall, DM
中科院分区：
文献类型：
--
作者：
Blacque, OE;Worrall, DM
Maspin（乳腺子宫蛋白酶抑制剂）最初被鉴定为人乳腺上皮细胞中的肿瘤抑制蛋白，并且是丝氨酸蛋白酶抑制剂（serpin）超家族的成员。它抑制肿瘤细胞运动和血管生成，虽然主要是细胞质，但也定位于细胞表面。在这项研究中，我们研究了使用酵母双杂交相互作用陷阱，以确定新的maspin目标。筛选靶向人成纤维细胞cDNA文库，并鉴定I型胶原的α-2链为潜在的相互作用物。与分离的蛋白质的结合研究表明，重组maspin和I型和III型胶原蛋白之间的相互作用，但不是其他胶原蛋白亚型，一个配置文件惊人的相似，小鼠色素上皮衍生因子（胱天蛋白），这是类似的下调小鼠腺癌肿瘤，是一种有效的血管生成抑制剂。使用IAsys共振镜生物传感器的动力学分析确定maspin对I型胶原的解离常数为0.63 μ m。与maspin截短构建体的进一步双杂交相互作用表明，胶原蛋白结合定位于maspin的氨基酸84-112，其与胶原蛋白结合区的colligin对齐。外源性或细胞表面maspin与细胞外基质胶原之间的直接相互作用可能有助于防止肿瘤细胞迁移和血管生成的细胞粘附作用。
Maspin (mammary uterine protease inhibitor) was originally identified as a tumor suppressor protein in human breast epithelial cells and is a member of the serine proteases inhibitor (serpin) superfamily. It inhibits tumor cell motility and angiogenesis, and although predominantly cytoplasmic, it is also localized to the cell surface. In this study we have investigated the use of the yeast two-hybrid interaction trap to identify novel maspin targets. A target human fibroblast cDNA library was screened, and the alpha-2 chain of type I collagen was identified as a potential interactant. Binding studies with isolated proteins showed interaction between recombinant maspin and types I and III collagen but not other collagen subtypes, a profile strikingly similar to mouse pigment epithelium-derived factor (caspin), which is similarly down-regulated in murine adenocarcinoma tumors and is a potent inhibitor of angiogenesis. Kinetic analysis using an IAsys resonant mirror biosensor determined the dissociation constant of maspin for collagen type I to be 0.63 mum. Further two-hybrid interactions with maspin truncation constructs suggest that collagen binding is localized to amino acids 84-112 of maspin, which aligns with the collagen-binding region of colligin. A direct interaction between exogenous or cell surface maspin and extracellular matrix collagen may contribute to a cell adhesion role in the prevention of tumor cell migration and angiogenesis.