Kretschmer Simon, Zieske Katja, Schwille Petra
Department of Cellular and Molecular Biophysics, Max Planck Institute of Biochemistry, Martinsried, Germany.
Graduate School of Quantitative Biosciences, Ludwig-Maximilians-Universität, München, Germany.
PLoS One. 2017 Jun 16;12(6):e0179582. doi: 10.1371/journal.pone.0179582. eCollection 2017.
The E. coli MinDE oscillator is a paradigm for protein self-organization and gradient formation. Previously, we reconstituted Min protein wave patterns on flat membranes as well as gradient-forming pole-to-pole oscillations in cell-shaped PDMS microcompartments. These oscillations appeared to require direct membrane interaction of the ATPase activating protein MinE. However, it remained unclear how exactly Min protein dynamics are regulated by MinE membrane binding. Here, we dissect the role of MinE's membrane targeting sequence (MTS) by reconstituting various MinE mutants in 2D and 3D geometries. We demonstrate that the MTS defines the lower limit of the concentration-dependent wavelength of Min protein patterns while restraining MinE's ability to stimulate MinD's ATPase activity. Strikingly, a markedly reduced length scale-obtainable even by single mutations-is associated with a rich variety of multistable dynamic modes in cell-shaped compartments. This dramatic remodeling in response to biochemical changes reveals a remarkable trade-off between robustness and versatility of the Min oscillator.
大肠杆菌MinDE振荡器是蛋白质自组织和梯度形成的范例。此前,我们在平面膜上重构了Min蛋白波模式,以及在细胞形状的聚二甲基硅氧烷(PDMS)微隔室中形成梯度的极对极振荡。这些振荡似乎需要ATP酶激活蛋白MinE与膜直接相互作用。然而,MinE膜结合究竟如何精确调节Min蛋白动力学仍不清楚。在这里,我们通过在二维和三维几何结构中重构各种MinE突变体来剖析MinE膜靶向序列(MTS)的作用。我们证明,MTS定义了Min蛋白模式浓度依赖性波长的下限,同时限制了MinE刺激MinD的ATP酶活性的能力。引人注目的是,即使通过单突变也能获得明显减小的长度尺度,这与细胞形状隔室中丰富多样的多稳态动态模式相关。这种响应生化变化的显著重塑揭示了Min振荡器在稳健性和通用性之间的显著权衡。