%0 Journal Article
%T Geometric conservation laws for cells or vesicles with membrane nanotubes or singular points
%A Yajun Yin
%A Jie Yin
%J Journal of Nanobiotechnology
%D 2006
%I BioMed Central
%R 10.1186/1477-3155-4-6
%X Cell-to-cell communication is one of the focuses in cell biology. In the past, three mechanisms for intercellular communication, i.e. chemical synapses, gap junctions and plasmodesmata, have been confirmed. Recently, new mechanism for long-distance intercellular communication is revealed. Rustoms et al. [1] discover that highly sensitive nanotubular structures may be formed de novo between cells. Except for living cells, liposomes and lipid bilayer vesicles with membrane nanotubes have also been found in experiments [2-5]. Impressive photos of membrane nanotubes interconnecting vesicles can be seen in Ref.[3]. Another beautiful photo of a membrane nanotube generated from a vesicle deformed by optical tweezers can be shown in Ref.[4].The above long-distance bionano structures may be of essential importance in cell biology and have drawn the attentions of researchers in different disciplines. Many annotations are concentrated on the formations of the membrane nanotubes. Different force generating processes such as the movement of motor proteins or the polymerization of cytoskeletal filaments have been suggested to be responsible for the tube formations in cells [6]. Of course, such annotations are absolutely necessary, but may not be sufficient. Another question with equal importance may be asked: Are there geometric conservation laws observed by such interesting bionano structures?To answer the above question, geometrical method will be used in this letter. As the first step, this paper will deal with the simplest "representative cell-nanotube element" (i.e. a cell or vesicle with membrane nanotubes). Then on the basis of the "element", vesicles with membrane nanotubes interconnected by a 2-way or 3-way nanotube junction will be investigated.Geometrically, a cell membrane or vesicle may be treated as a curved surface or 2D Riemann manifold. The generalized situation of a smooth curved surface is shown in Fig. 1. Let n be the outward unit normal of the surface and C b
%U http://www.jnanobiotechnology.com/content/4/1/6