Molecular Immunology Unit, Hospital Universitario Puerta de Hierro, Majadahonda, Madrid, Spain.
PLoS One. 2012;7(6):e39097. doi: 10.1371/journal.pone.0039097. Epub 2012 Jun 19.
Laminins are large heterotrimeric cross-shaped extracellular matrix glycoproteins with terminal globular domains and a coiled-coil region through which the three chains are assembled and covalently linked. Laminins are key components of basement membranes, and they serve as attachment sites for cell adhesion, migration and proliferation. In this work, we produced a recombinant fragment comprising the entire laminin coiled-coil of the α1-, β1-, and γ1-chains that assemble into a stable heterotrimeric coiled-coil structure independently of the rest of the molecule. This domain was biologically active and not only failed to serve as a substrate for cell attachment, spreading and focal adhesion formation but also inhibited cell adhesion to laminin when added to cells in a soluble form at the time of seeding. Furthermore, gene array expression profiling in cells cultured in the presence of the laminin coiled-coil domain revealed up-regulation of genes involved in cell motility and invasion. These findings were confirmed by real-time quantitative PCR and zymography assays. In conclusion, this study shows for the first time that the laminin coiled-coil domain displays anti-adhesive functions and has potential implications for cell migration during matrix remodeling.
层粘连蛋白是一种大型异三聚体十字形细胞外基质糖蛋白，具有末端球形结构域和一个卷曲螺旋区，三条链通过该卷曲螺旋区组装并共价连接。层粘连蛋白是基底膜的主要成分，它们作为细胞附着、迁移和增殖的附着点。在这项工作中，我们生产了一种重组片段，该片段包含α1、β1 和γ1 链的整个层粘连蛋白卷曲螺旋，这些卷曲螺旋独立于分子的其余部分组装成稳定的异三聚体卷曲螺旋结构。该结构域具有生物活性，不仅不能作为细胞附着、铺展和焦点形成的底物，而且当以可溶性形式在接种时添加到细胞中时，还能抑制细胞对层粘连蛋白的附着。此外，在存在层粘连蛋白卷曲螺旋结构域的细胞中进行基因表达谱分析显示，与细胞迁移和侵袭相关的基因上调。这些发现通过实时定量 PCR 和酶谱分析得到证实。总之，这项研究首次表明，层粘连蛋白卷曲螺旋结构域具有抗粘附功能，在基质重塑过程中对细胞迁移具有潜在意义。
