Department of Mechanical and Aerospace Engineering, University of California San Diego, San Diego, CA, 92093, USA.
Department of Physics, New York Institute of Technology, New York, NY, 11568, USA.
Sci Rep. 2020 Feb 13;10(1):2527. doi: 10.1038/s41598-020-59221-x.
Membrane nanotubes are dynamic structures that may connect cells over long distances. Nanotubes are typically thin cylindrical tubes, but they may occasionally have a beaded architecture along the tube. In this paper, we study the role of membrane mechanics in governing the architecture of these tubes and show that the formation of bead-like structures along the nanotubes can result from local heterogeneities in the membrane either due to protein aggregation or due to membrane composition. We present numerical results that predict how membrane properties, protein density, and local tension compete to create a phase space that governs the morphology of a nanotube. We also find that there exists a discontinuity in the energy that impedes two beads from fusing. These results suggest that the membrane-protein interaction, membrane composition, and membrane tension closely govern the tube radius, number of beads, and the bead morphology.
细胞膜纳米管是一种动态结构，可在长距离连接细胞。纳米管通常是细圆柱形管，但它们偶尔会沿着管形成珠状结构。在本文中，我们研究了膜力学在控制这些管结构中的作用，并表明珠状结构的形成是由于膜中的局部异质性，这种异质性可能是由于蛋白质聚集或膜成分引起的。我们提出了数值结果，预测了膜性质、蛋白质密度和局部张力如何相互竞争，以创建一个控制纳米管形态的相空间。我们还发现，存在一个能量不连续，阻止两个珠状物融合。这些结果表明，膜-蛋白相互作用、膜成分和膜张力密切控制着管半径、珠状物数量和珠状物形态。
