Max Planck Institute of Colloids and Interfaces, Department of Theory and Bio-Systems, Potsdam, Germany.
PLoS One. 2011;6(8):e23284. doi: 10.1371/journal.pone.0023284. Epub 2011 Aug 17.
Submicron scale domains of membrane-anchored receptors play an important role in cell signaling. Central questions concern the stability of these microdomains, and the mechanisms leading to the domain formation. In immune-cell adhesion zones, microdomains of short receptor-ligand complexes form next to domains of significantly longer receptor-ligand complexes. The length mismatch between the receptor-ligand complexes leads to membrane deformations and has been suggested as a possible cause of the domain formation. The domain formation is a nucleation and growth process that depends on the line tension and free energy of the domains. Using a combination of analytical calculations and Monte Carlo simulations, we derive here general expressions for the line tension between domains of long and short receptor-ligand complexes and for the adhesion free energy of the domains. We argue that the length mismatch of receptor-ligand complexes alone is sufficient to drive the domain formation, and obtain submicron-scale minimum sizes for stable domains that are consistent with the domain sizes observed during immune-cell adhesion.
膜锚定受体的亚微米尺度域在细胞信号转导中发挥着重要作用。核心问题涉及这些微域的稳定性以及导致域形成的机制。在免疫细胞黏附区，短受体-配体复合物的微域紧邻受体-配体复合物长度显著更长的域形成。受体-配体复合物之间的长度不匹配会导致膜变形，并被认为是域形成的可能原因。域形成是一个成核和生长过程，取决于域的线张力和自由能。我们使用分析计算和蒙特卡罗模拟的组合，在此推导出长和短受体-配体复合物域之间的线张力以及域的粘附自由能的一般表达式。我们认为，受体-配体复合物的长度不匹配本身足以驱动域形成，并获得与免疫细胞黏附过程中观察到的域大小一致的稳定域的亚微米级最小尺寸。
