Whited Allison M, Park Paul S-H
Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA.
Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA.
Biochim Biophys Acta. 2015 Jan;1848(1 Pt A):26-34. doi: 10.1016/j.bbamem.2014.10.007. Epub 2014 Oct 12.
Biological membranes display distinct domains that organize membrane proteins and signaling molecules to facilitate efficient and reliable signaling. The organization of rhodopsin, a G protein-coupled receptor, in native rod outer segment disc membranes was investigated by atomic force microscopy. Atomic force microscopy revealed that rhodopsin is arranged into domains of variable size, which we refer to herein as nanodomains, in native membranes. Quantitative analysis of 150 disc membranes revealed that the physical properties of nanodomains are conserved in humans and mice and that the properties of individual disc membranes can be variable. Examining the variable properties of disc membranes revealed some of the factors contributing to the size of rod outer segment discs and the formation of nanodomains in the membrane. The diameter of rod outer segment discs was dependent on the number of rhodopsin molecules incorporated into the membrane but independent of the spatial density of rhodopsin. The number of nanodomains present in a single disc was also dependent on the number of rhodopsin molecules incorporated into the membrane. The size of the nanodomains was largely independent of the number or spatial density of rhodopsin in the membrane.
生物膜呈现出不同的结构域，这些结构域可组织膜蛋白和信号分子，以促进高效且可靠的信号传导。利用原子力显微镜研究了视紫红质（一种G蛋白偶联受体）在天然视杆细胞外段盘状膜中的组织方式。原子力显微镜显示，在天然膜中视紫红质排列成大小可变的结构域，在此我们将其称为纳米结构域。对150个盘状膜进行的定量分析表明，纳米结构域的物理特性在人类和小鼠中是保守的，并且单个盘状膜的特性可能存在差异。研究盘状膜的可变特性揭示了一些影响视杆细胞外段盘大小以及膜中纳米结构域形成的因素。视杆细胞外段盘的直径取决于掺入膜中的视紫红质分子数量，但与视紫红质的空间密度无关。单个盘中存在的纳米结构域数量也取决于掺入膜中的视紫红质分子数量。纳米结构域的大小在很大程度上与膜中视紫红质的数量或空间密度无关。
