Dual biochemical oscillators may control cellular reversals in Myxococcus xanthus.
Dual biochemical oscillators may control cellular reversals in Myxococcus xanthus.
复制标题
双生化振荡器可以控制黄色粘球菌的细胞逆转。
DOI：
10.1016/j.bpj.2014.09.046
复制
发表时间：
2014
影响因子：
3.4
通讯作者：
Berleman,JamesE
中科院分区：
文献类型：
--
作者：
Eckhert,Erik;Rangamani,Padmini;Davis,AnnieE;Oster,George;Berleman,JamesE
黄色粘球菌是一种革兰氏阴性的土壤细菌，在表面上滑动，大约每6分钟反转一次方向。黄色分枝杆菌的运动性由Che样Frz途径和Ras样Mgl途径控制，它们共同导致细胞来回振荡。此前，Igoshin et al.（2004）提出细胞振荡是由控制运动性的活性Frz蛋白浓度的周期性变化引起的。在这项研究中，我们提出了一个计算模型，集成了Frz和Mgl途径，其下游组件可以被读取为电机活动控制细胞逆转。该模型通过模拟单个蛋白质敲除忠实地再现了野生型和突变型行为。此外，该模型可用于研究接触刺激对细胞逆转的影响。基本模型的构建依赖于两个嵌套的反馈回路的存在，这促使我们重新研究M. xanthus细胞的行为。我们进行了实验来测试该模型，并且该细胞分析挑战了先前的30至60分钟逆转期的假设infrzCD、frzF、frzE和frzZ突变体。我们证明，这一平均逆转周期是一个人工制品的方法，采用记录逆转数据，并在没有信号从Frz途径，镁成分可以偶尔扭转野生型周期附近的细胞，butfrz-细胞，否则在一个长期的非振荡状态。
Myxococcus xanthusis a Gram-negative, soil-dwelling bacterium that glides on surfaces, reversing direction approximately once every 6 min. Motility inM. xanthusis governed by the Che-like Frz pathway and the Ras-like Mgl pathway, which together cause the cell to oscillate back and forth. Previously, Igoshin et al. (2004) suggested that the cellular oscillations are caused by cyclic changes in concentration of active Frz proteins that govern motility. In this study, we present a computational model that integrates both the Frz and Mgl pathways, and whose downstream components can be read as motor activity governing cellular reversals. This model faithfully reproduces wildtype and mutant behaviors by simulating individual protein knockouts. In addition, the model can be used to examine the impact of contact stimuli on cellular reversals. The basic model construction relies on the presence of two nested feedback circuits, which prompted us to reexamine the behavior ofM. xanthuscells. We performed experiments to test the model, and this cell analysis challenges previous assumptions of 30 to 60 min reversal periods infrzCD,frzF,frzE, andfrzZmutants. We demonstrate that this average reversal period is an artifact of the method employed to record reversal data, and that in the absence of signal from the Frz pathway, Mgl components can occasionally reverse the cell near wildtype periodicity, butfrz- cells are otherwise in a long nonoscillating state.