The cell substrate attachment (CSAT) antigen has properties of a receptor for laminin and fibronectin.
The cell substrate attachment (CSAT) antigen has properties of a receptor for laminin and fibronectin.
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DOI：
10.1083/jcb.101.6.2134
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发表时间：
1985-12
期刊：
影响因子：
--
通讯作者：
Buck C
中科院分区：
文献类型：
--
作者：
Horwitz A;Duggan K;Greggs R;Decker C;Buck C
细胞基质附着（CSAT）抗原是一种完整的膜糖蛋白复合物，参与细胞与细胞外分子的粘附。针对该复合物的CSAT单克隆抗体抑制心脏和肌腱成纤维细胞和骨骼肌成肌细胞与层粘连蛋白和纤连蛋白的粘附，从而暗示CSAT抗原与这些细胞外分子的粘附。平衡凝胶过滤用于探索CSAT抗原作为层粘连蛋白和纤连蛋白的细胞表面受体的假设。在该技术中，设计用于快速交换平衡，凝胶过滤柱用细胞外配体预平衡，以确保在其通过柱的过程中受体占据。层粘连蛋白和纤连蛋白均与CSAT抗原形成复合物。与层粘连蛋白的协会被抑制的CSAT单克隆抗体，与纤连蛋白和层粘连蛋白的协会被抑制的合成肽含有纤连蛋白细胞结合序列。平衡凝胶过滤的解离常数的估计同意与其他测量。这表明这些关联具有生物学意义。SDS PAGE显示，所有三个糖蛋白组成的CSAT抗原存在于抗原-配体复合物。凝胶过滤和速度沉降表明，这三个条带包括寡聚复合物，这为它们的功能关联提供了解释。CSAT单克隆抗体对粘附的抑制以及纯化的抗原与细胞外配体的结合被解释为强烈暗示CSAT抗原是纤连蛋白和层粘连蛋白的受体，也可能是其他细胞外分子的受体。
The cell substrate attachment (CSAT) antigen is an integral membrane glycoprotein complex that participates in the adhesion of cells to extracellular molecules. The CSAT monoclonal antibody, directed against this complex, inhibited adhesion of cardiac and tendon fibroblasts and skeletal myoblasts to both laminin and fibronectin, thus implicating the CSAT antigen in adhesion to these extracellular molecules. Equilibrium gel filtration was used to explore the hypothesis that the CSAT antigen functions as a cell surface receptor for both laminin and fibronectin. In this technique, designed for rapidly exchanging equilibria, the gel filtration column is pre-equilibrated with extracellular ligand to ensure receptor occupancy during its journey through the column. Both laminin and fibronectin formed complexes with the CSAT antigen. The association with laminin was inhibited by the CSAT monoclonal antibody; the associations with both fibronectin and laminin were inhibited by synthetic peptides containing the fibronectin cell-binding sequence. Estimates of the dissociation constants by equilibrium gel filtration agree well with those available from other measurements. This suggests that these associations are biologically significant. SDS PAGE showed that all three glycoproteins comprising the CSAT antigen were present in the antigen-ligand complexes. Gel filtration and velocity sedimentation were used to show that the three bands comprise and oligomeric complex, which provides an explanation for their functional association. The inhibition of adhesion by the CSAT monoclonal antibody and the association of the purified antigen with extracellular ligands are interpreted as strongly implicating the CSAT antigen as a receptor for both fibronectin and laminin and perhaps for other extracellular molecules as well.