Adhesion of cultured human kidney mesangial cells to native entactin: Role of integrin receptors
Adhesion of cultured human kidney mesangial cells to native entactin: Role of integrin receptors
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DOI：
10.3109/15419069809040294
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发表时间：
1998-01-01
期刊：
影响因子：
--
通讯作者：
Fish, AJ
中科院分区：
文献类型：
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作者：
Yi, XY;Wayner, EA;Fish, AJ
Entactin 是一种与层粘连蛋白结合的细胞外基质糖蛋白，存在于大多数肾基底膜和肾小球系膜基质中。在本研究中，我们表征了培养的人系膜细胞（CHMC）上负责粘附天然巢蛋白的特定整合素受体。与β1或β4复合的整联蛋白受体α2β1、α3β1、α5β1、αvβ3、αvβ5和α6可以从代谢标记的CHMC的洗涤剂提取物中免疫沉淀。使用抑制性抗整合素单克隆抗体 (mab) 进行的粘附测定表明，CHMC 使用 α v beta 3 和含有 β 1 的整合素来结合涂有天然巢蛋白的表面。 CHMC 与天然巢蛋白的最佳结合需要阳离子的参与。使用野生型和突变体重组内动蛋白片段，将αvβ3受体的结合位点定位于内动蛋白的杆或E结构域上的RGD序列。 CHMC 与缺乏 E 结构域 RGD 序列的突变型全长重组巢蛋白配体的粘附证实了 β1 整联蛋白受体的配体结合位点的存在。观察到与天然牛基底膜巢蛋白相比，CHMC 与重组和全长巢蛋白的结合特征存在差异。这表明三级分子结构可能有助于巢蛋白配体结合特性。巢蛋白的一级氨基酸残基序列和三级结构可能在天然基底膜巢蛋白中形成功能性细胞附着位点中发挥作用。
Entactin is an extracellular matrix glycoprotein which binds to laminin and is found in most renal basement membranes and in the glomerular mesangial matrix. In the present study, we have characterized specific integrin receptors on cultured human mesangial cells (CHMC) responsible for adhesion to native entactin. The integrin receptors alpha 2 beta 1, alpha 3 beta 1, alpha 5 beta 1, alpha v beta 3, alpha v beta 5, and alpha 6 complexed with either beta 1 or beta 4 could be immune precipitated from detergent extracts of metabolically labeled CHMC. Adhesion assays with inhibitory anti integrin monoclonal antibodies (mab) demonstrated that CHMC use both alpha v beta 3 and a beta 1-containing integrin to bind surfaces coated with native entactin. Optimal binding of CHMC to native entactin required the participation of cations. Using wild type and mutant recombinant entactin fragments, the binding site for the alpha v beta 3 receptor was localized to the RGD sequence on the rod or E domain of entactin. CHMC adhesion to mutant full length recombinant entactin ligands lacking the E domain RGD sequence confirmed the presence of ligand binding site(s) for beta 1 integrin receptor(s). Differences in CHMC binding characteristics to recombinant and full length entactin compared to native bovine basement membrane entactin were observed. This suggests that tertiary molecular structure may contribute to entactin ligand binding properties. Primary amino acid residue sequences and tertiary structure of entactin may play roles in forming functional cell attachment sites in native basement membrane entactin.