Isomorphic coalescence of aster cores formed in vitro from microtubules and kinesin motors. (21st September 2016)

• Record Type: Journal Article
• Authors: Kim, K; Sikora, A; Nakazawa, H; Umetsu, M; Hwang, W; Teizer, W
• Is Part Of: Physical biology. Volume 13:Number 5(2016:Oct.)
• Publication Date: 2016-09-21
• Subjects: microtubule -- kinesin -- aster -- emergence; Biophysics -- Periodicals; Biochemistry -- Periodicals; Biology -- Data processing -- Periodicals; 570.5
• DOI: 10.1088/1478-3975/13/5/056002
• Languages: English
• ISSNs: 1478-3967

Abstract

Abstract: We report fluorescence microscopy studies of the formation of aster-like structures emerging from a cellular element-based active system and a novel analysis of the aster condensation. The system consists of rhodamine labeled microtubules which are dynamically coupled by functionalized kinesin motor proteins cross-linked via streptavidin-coated quantum dots (QDs). The aster-shaped objects contain core structures. The cores are aggregates of the QD-motor protein complexes, and result from the dynamic condensation of sub-clusters that are connected to each other randomly. The structural specificity of the aster core reflects a configuration of the initial connectivity between sub-clusters. Detailed image analysis allows us to extract a novel correlation between the condensation speed and the sub-cluster separation. The size of the core is scaled down during the condensation process, following a power law dependence on the distance between sub-clusters. The exponent of the power law is close to two, as expected from a geometric model. This single exponent common to all the contractile lines implies that there exists a time regime during which an isomorphic contraction of the aster core continues during the condensation process. We analyze the observed contraction by using a model system with potential applicability in a wide range of emergent phenomena in randomly coupled active networks, which are prevalent in the cellular environment.