Urokinase plasminogen activator receptor, beta 2-integrins, and Src-kinases within a single receptor complex of human monocytes.
Urokinase plasminogen activator receptor, beta 2-integrins, and Src-kinases within a single receptor complex of human monocytes.
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DOI：
10.1084/jem.181.4.1381
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发表时间：
1995-04-01
期刊：
影响因子：
--
通讯作者：
Stockinger H
中科院分区：
文献类型：
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作者：
Bohuslav J;Horejsí V;Hansmann C;Stöckl J;Weidle UH;Majdic O;Bartke I;Knapp W;Stockinger H
糖基磷脂酰肌醇（GPI）锚定的膜蛋白尿激酶纤溶酶原激活物受体（uPA-R; CD 87）是参与白细胞和肿瘤细胞迁移的关键分子之一。与uPA-R结合的uPA提供用于降解细胞外基质的细胞蛋白水解潜力。uPA-R还参与细胞粘附和趋化性的诱导。在这里，我们为这些uPA-R相关的细胞事件提供了分子解释。通过对单核细胞裂解物的大小分级分离和对其天然配体uPA的亲和分离，我们证明uPA-R是相对较大大小的受体复合物的组分。再沉淀和免疫印迹技术使我们能够检测蛋白酪氨酸激酶（PTKs）p60 fyn，p53/56 lyn，p58/64 hck和p59 fgr作为这种“uPA-R复合物”的组分。即使用酶失活的uPA激活单核细胞也导致酪氨酸磷酸化的诱导，表明在配体结合后uPA-R相关PTKs的调节。尽管它们存在于大的复合物中，但我们在uPA-R复合物中没有发现GPI连接的蛋白CD 14、CD 58和CD 59，这表明单核细胞中存在含有GPI连接的蛋白的不同受体结构域。然而，我们确定了白细胞整合素LFA-1和CR 3作为uPA-R复合物的组成部分，如通过这些分子的共分离以及通过uPA-R和白细胞整合素在单核细胞表面上的共封端和共调节所指示的。uPA-R、PTK和跨膜β 2-整联蛋白在一个受体复合物中的组装表明功能合作。关于这些分子参与细胞周围的蛋白水解，信号转导，以及粘附和趋化运动，我们建议uPA-R复合物作为一个潜在的细胞迁移装置。
The glycosylphosphatidylinositol (GPI)-anchored membrane protein urokinase plasminogen activator-receptor (uPA-R; CD87) is one of the key molecules involved in migration of leukocytes and tumor cells. uPA bound to uPA-R provides the cell proteolytic potential used for degradation of extracellular matrix. uPA-R is also involved in induction of cell adhesion and chemotaxis. Here, we provide a molecular explanation for these uPA-R-related cellular events. By size fractionation of monocyte lysate and affinity isolation on its natural ligand uPA, we demonstrate uPA-R as a component of a receptor complex of relatively large size. Reprecipitation and immunoblotting techniques allowed us to detect the protein tyrosine kinases (PTKs) p60fyn, p53/56lyn, p58/64hck, and p59fgr as components of this "uPA-R complex". Activation of monocytes even with enzymatically inactivated uPA resulted in induction of tyrosine phosphorylation, suggesting modulation of uPA-R-associated PTKs upon ligand binding. In spite of their presence in large complexes, we did not find the GPI-linked proteins CD14, CD58, and CD59 in the uPA-R complex, which indicates the presence of different receptor domains containing GPI-linked proteins in monocytes. However, we identified the leukocyte integrins LFA-1 and CR3 as components of the uPA-R complex as indicated by coisolation of these molecules, as well as by cocapping and comodulation of uPA-R and leukocyte integrins on the monocyte surface. The assemblage of uPA-R, PTKs and membrane spanning beta 2-integrins in one receptor complex indicates functional cooperation. In regard to the involvement of these molecules in pericellular proteolysis, signal transduction, as well as adhesion and chemotactic movement, we suggest uPA-R complex as a potential cellular device for cell migration.