Structural polymorphism of the cytoskeleton: A model of linker-assisted filament aggregation

被引:88
作者
Borukhov, L
Bruinsma, RF
Gelbart, WM
Liu, AJ
机构
[1] Univ Penn, Dept Phys & Astron, Philadelphia, PA 19104 USA
[2] Univ Calif Los Angeles, Dept Chem & Biochem, Los Angeles, CA 90095 USA
[3] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA
关键词
actin; bundle; liquid crystal; network;
D O I
10.1073/pnas.0404140102
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
The phase behavior of charged rods in the presence of interrod linkers is studied theoretically as a model for the equilibrium behavior underlying the organization of actin filaments by linker proteins in the cytoskeleton. The presence of linkers in the solution modifies the effective interrod interaction and can lead to interfilament attraction. Depending on the composition and physical properties of the system, such as linker-binding energies, filaments will orient either perpendicular or parallel to each other, leading to network-like or bundled structures. We show that such a system can have one of three generic phase diagrams, one dominated by bundles, another by networks, and the third containing both bundle and network-like phases. The first two diagrams can be found over a wide range of interaction energies, whereas the third diagram occurs only for a narrow range. These results provide theoretical understanding of the classification of linker proteins as bundling proteins or crosslinking proteins. in addition, they suggest possible mechanisms by which the cell may control cytoskeletal morphology.
引用
收藏
页码:3673 / 3678
页数:6
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