Erickson A C, Couchman J R
Department of Cell Biology and Cell Adhesion and Matrix Research Center, University of Alabama at Birmingham, Birmingham, Alabama 35294-0019, USA.
J Histochem Cytochem. 2000 Oct;48(10):1291-306. doi: 10.1177/002215540004801001.
At the epithelial/mesenchymal interface of most tissues lies the basement membrane (BM). These thin sheets of highly specialized extracellular matrix vary in composition in a tissue-specific manner, and during development and repair. For about two decades it has been apparent that all BMs contain laminins, entactin-1/nidogen-1, Type IV collagen, and proteoglycans. However, within the past few years this complexity has increased as new components are described. The entactin/nidogen (E/N) family has expanded with the recent description of a new isoform, E/N-2/osteonidogen. Agrin and Type XVIII collagen have been reclassified as heparan sulfate proteoglycans (HSPGs), expanding the repertoire of HSPGs in the BM. The laminin family has become more diverse as new alpha-chains have been characterized, increasing the number of laminin isoforms. Interactions between BM components are now appreciated to be regulated through multiple, mostly domain-specific mechanisms. Understanding the functions of individual BM components and their assembly into macromolecular complexes is a considerable challenge that may increase as further BM and cell surface ligands are discovered for these proteins.
在大多数组织的上皮/间充质界面处存在着基底膜（BM）。这些由高度特化的细胞外基质构成的薄片在组成上因组织特异性方式以及在发育和修复过程中而有所不同。大约二十年来，很明显所有的基底膜都包含层粘连蛋白、内动蛋白-1/巢蛋白-1、IV型胶原蛋白和蛋白聚糖。然而，在过去几年中，随着新成分的被描述，这种复杂性增加了。内动蛋白/巢蛋白（E/N）家族随着最近一种新亚型E/N-2/骨巢蛋白的被描述而得到扩展。聚集蛋白和XVIII型胶原蛋白已被重新归类为硫酸乙酰肝素蛋白聚糖（HSPG），从而扩大了基底膜中硫酸乙酰肝素蛋白聚糖的种类。随着新的α链被鉴定，层粘连蛋白家族变得更加多样，增加了层粘连蛋白亚型的数量。现在认识到基底膜成分之间的相互作用是通过多种主要是结构域特异性的机制来调节的。理解单个基底膜成分的功能及其组装成大分子复合物是一项相当大的挑战，随着针对这些蛋白质发现更多的基底膜和细胞表面配体，这一挑战可能会增加。
