Modulation of the reaction rate of regulating protein induces large morphological and motional change of amoebic cell
Modulation of the reaction rate of regulating protein induces large morphological and motional change of amoebic cell
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DOI：
10.1016/j.jtbi.2006.09.027
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发表时间：
2007-03-21
影响因子：
2
通讯作者：
Sasai, Masaki
中科院分区：
文献类型：
--
作者：
Nishimura, Shin I.;Sasai, Masaki
移动变形虫的形态分为两类。一种是“中性粒细胞”型，细胞的长轴大致与其移动方向一致。这种类型的细胞在前面延伸出一个前缘，在后面缩回一个狭窄的尾巴，其形状在教科书中经常被描绘成典型的变形虫。另一种是“角膜细胞”型，沿前侧弧沿着分布广泛的板状伪足。这种类型细胞的短轴与其运动方向大致一致。为了了解什么样的分子特征导致两种形态之间的转换，以及两种典型形态是如何保持的，发展了一个阿米巴细胞的数学模型。该模型以统一的方式描述了细胞的运动以及激活剂、抑制剂和肌动蛋白丝在细胞内的反应。结果表明，活化剂的产率是影响两种类型转化率的关键因素。该模型还解释了观察到的数据，即角膜细胞型细胞倾向于沿沿着直线快速移动。当移动速度小时，中性粒细胞型细胞沿着直线移动，但是当它们与角膜细胞型细胞一样快地移动时，它们显示偏离直线的波动运动。预测了中性粒细胞型细胞中的有效能量消耗。(c)2006年由Elsevier Ltd.出版
Morphologies of moving amoebae are categorized into two types. One is the "neutrophil" type in which the long axis of cell roughly coincides with its moving direction. This type of cell extends a leading edge at the front and retracts a narrow tail at the rear, whose shape has been often drawn as a typical amoeba in textbooks. The other one is the "keratocyte" type with widespread lamellipodia along the front side arc. Short axis of cell in this type roughly coincides with its moving direction. In order to understand what kind of molecular feature causes conversion between two types of morphologies, and how two typical morphologies are maintained, a mathematical model of amoebic cells is developed. This model describes movement of cell and intracellular reactions of activator, inhibitor and actin filaments in a unified way. It is found that the producing rate of activator is a key factor of conversion between two types. This model also explains the observed data that the keratocyte type cells tend to rapidly move along a straight line. The neutrophil type cells move along a straight line when the moving velocity is small, but they show fluctuated motions deviating from a line when they move as fast as the keratocyte type cells. Efficient energy consumption in the neutrophil type cells is predicted. (c) 2006 Published by Elsevier Ltd.