Characterization of a tight molecular complex between integrin α6β4 and laminin-5 extracellular matrix
Characterization of a tight molecular complex between integrin α6β4 and laminin-5 extracellular matrix
复制标题
DOI：
10.1006/bbrc.1998.9400
复制
发表时间：
1998-10-09
影响因子：
3.1
通讯作者：
Quaranta, V
中科院分区：
文献类型：
--
作者：
Falk-Marzillier, J;Domanico, SZ;Quaranta, V
在许多成人上皮细胞中，如表皮或肠道，上皮细胞与基底膜的黏附需要整合素α6β4和层粘连蛋白5(Ln-5)。如果没有其中之一，就会发生广泛的起泡和剥落。虽然有报道称α6β4是Ln-5的受体，但这种相互作用却知之甚少。我们在804G上皮细胞系细胞外基质(ECM)的无细胞制备中表征了α6β4和Ln-5之间的络合物。通过显微测序，Ln-5和α6β4是ECM中的主要蛋白质，可能参与了受体/配体复合体，因为免疫荧光显示，在细胞单层和无细胞ECM制备中，α6β4与Ln-5共存，但在单层与α6β4或Ln-5功能阻断抗体预孵育后，它们消失了。α6β4/Ln-5络合物能抵抗极端pH、尿素、共沸物、EDTA、非离子洗涤剂和b-巯基乙醇的解离。它们只能被强阴离子去污剂解离，例如1%的十二烷基硫酸钠，这表明受体/配体之间的相互作用是基于高亲和力或亲和力的。我们认为这些α6β4/Ln-5复合体可能在细胞膜和基底膜之间提供联系，以抵抗机械应力并支持上皮的完整性。(C)1998年学术出版社。
In many adult epithelia, e.g., epidermis or intestine, adhesion of epithelial cells to basement membrane requires the integrin alpha 6 beta 4 and laminin-5 (Ln-5). In the absence of one or the other, extensive blistering and exfoliation occur. While alpha 6 beta 4 was reported to be a receptor for Ln-5, this interaction is poorly understood. We characterize complexes between alpha 6 beta 4 and Ln-5 in cell-free preparations of extracellular matrix (ECM) from the epithelial cell line, 804G. By microsequencing, Ln-5 and alpha 6 beta 4 were the major proteins in this ECM and were likely engaged in receptor/ligand complexes because, by immunofluorescence, alpha 6 beta 4 was colocalized with Ln-5 both in cell monolayers and in cell-free ECM preparations, but they disappeared after preincubation of the monolayers with alpha 6 beta 4 or Ln-5 function-blocking antibodies. The alpha 6 beta 4/Ln-5 complexes were resistant to dissociation by extreme pH, urea, chaotropes, eDTA, non-ionic detergents, and b-mercaptoethanol. They were only dissociated by strong anionic detergents, e.g., 1% SDS, suggesting receptor/ligand interactions based on high affinity or avidity. We propose that these alpha 6 beta 4/Ln-5 complexes may provide links between plasma membrane and basement membrane that resist mechanical stress and support epithelial integrity. (C) 1998 Academic Press.