Cell attachment to thrombospondin: the role of ARG-GLY-ASP, calcium, and integrin receptors.
Cell attachment to thrombospondin: the role of ARG-GLY-ASP, calcium, and integrin receptors.
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细胞对血小板传播的附着：Arg-Gly-Asp，钙和整联蛋白受体的作用。
DOI：
10.1083/jcb.107.6.2351
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发表时间：
1988-12
影响因子：
7.8
通讯作者：
Hynes, R O
中科院分区：
文献类型：
--
作者：
Lawler, J;Weinstein, R;Hynes, R O
血小板反应蛋白是一种420，000-D的糖蛋白，最近已被证明与一类粘附蛋白的成员具有几种共同的性质。为了进一步表征血小板反应蛋白的粘附特性，我们研究了其支持细胞粘附的能力。血小板反应蛋白吸附到塑料培养皿支持人内皮细胞和平滑肌细胞以及单核细胞样细胞系（U937）以及正常大鼠肾细胞的附着。大多数附着的细胞不会在固相血小板反应蛋白上扩散。如果在EGTA存在下进行测定，则所有四种细胞类型对血小板反应蛋白的附着被消除，尽管细胞仍然附着于纤连蛋白。如果血小板反应蛋白在EGTA存在下吸附到培养皿上，然后在加入细胞之前用含有钙的缓冲液洗涤，则附着仍被显著抑制，表明钙影响血小板反应蛋白的构象和功能。所有四种细胞类型的附着也被合成肽gly-Arg-gly-asp-ser-pro（GRG-DSP）和gly-Arg-gly-asp-ala-cys（GRGDAC）显著抑制，但不被对照肽gly-Arg-gly-glu-ser-pro（GRG-ESP）抑制。在血小板反应蛋白-琼脂糖和GRG-DSP-Affigel柱上，使用表面标记的内皮细胞或平滑肌细胞的正辛基葡糖苷提取物的亲和色谱法来鉴定与糖蛋白IIb-IIIa相关的整合素复合物作为血小板反应蛋白的RGD依赖性受体。此外，阻断内皮细胞与玻连蛋白、纤维蛋白原和血管性血友病因子附着的单克隆抗体（LM 609）也抑制内皮细胞与血小板反应蛋白的附着。这些数据表明，细胞对血小板反应蛋白的附着是由RGD和钙依赖性机制介导的，并且与血小板反应蛋白中的GRGDAC序列是与β 3亚类整联蛋白受体相互作用的位点的假设一致。
Thrombospondin is a 420,000-D glycoprotein that has recently been shown to have several properties in common with the members of a class of adhesive proteins. To characterize further the adhesive properties of thrombospondin, we have studied its ability to support cell attachment. Thrombospondin adsorbed to plastic dishes supports the attachment of human endothelial and smooth muscle cells and the monocyte-like cell line (U937) as well as normal rat kidney cells. The majority of attached cells do not spread on the solid-phase thrombospondin. The attachment of all four cell types to thrombospondin is abolished if the assay is performed in the presence of EGTA, although the cells still attach to fibronectin. If thrombospondin is adsorbed to the dishes in the presence of EGTA and then washed with buffer containing calcium before addition of the cells, attachment is still markedly inhibited, indicating that calcium affects the conformation and function of thrombospondin. Attachment of all four cell types is also markedly inhibited by the synthetic peptides gly-arg-gly-asp-ser-pro (GRG-DSP) and gly-arg-gly-asp-ala-cys (GRGDAC) but not by the control peptide gly- arg-gly-glu-ser-pro (GRG-ESP). Affinity chromatography of n- octylglucoside extracts of surface-labeled endothelial cells or smooth muscle cells on thrombospondin-Sepharose and GRG-DSP-Affigel columns was used to identify an integrin complex related to glycoprotein IIb- IIIa as an RGD-dependent receptor for thrombospondin. In addition, a monoclonal antibody (LM609) that blocks attachment of endothelial cells to vitronectin, fibrinogen, and von Willebrand factor also inhibits attachment of endothelial cells to thrombospondin. These data indicate that the attachment of cells to thrombospondin is mediated by RGD and calcium-dependent mechanisms and is consistent with the hypothesis that the GRGDAC sequence in thrombospondin is a site for interaction with an integrin receptor of the beta 3 subclass.