(Link-Sign-Mech-Furr) Linking Signalling to Mechanics and Shape Changes in Mitotic Furrowing

在有丝分裂期间，细胞经历复杂的形状变化，在那里它们变圆，伸长并组装分裂沟。形状的变化出现在一个复杂的信号网络控制的皮层张力时空梯度的反应。皮质张力的模式由RhoGTP酶的活性控制，RhoGTP酶是细胞骨架和收缩性的关键调节剂。它们受一组不同的RhoGEFs/RhoGAP的调节，并且这些到膜模式的张力梯度的时空募集。我们不知道为什么多个RhoGEFs和RhoGAP在空间和时间上重叠，以控制犁沟的形成和侵入。虽然我们知道沟内移需要肌球蛋白收缩性的增加和皮质的重组，但我们不知道每个RhoGEF/GAP如何促成这些事件。我的总体目标是确定RhoGEFs/GAP的时空募集如何控制细胞力学，以驱动开沟过程中的形状变化。首先，分子，结构和机械的变化，在开沟的特点。将研究每个RhoGEF/GAP参与开沟引起的分子和机械变化。然后，RhoGEFs/GAP的相互作用将被检查。我将使用光学活和超分辨率显微镜和原子力显微镜的组合来研究结构和力学变化。为了确定每个RhoGEF/GAP的作用，我将设计能够时空控制信号的光遗传学执行器。通过结合两个执行器，我将研究RhoGEFs/GAP之间的相互作用。我将使用的结果作为输入参数的计算模型的细胞形状变化的基础上的时空定位的信号。

During mitosis, cells undergo complex shape changes, where they round up, elongate and assemble a division furrow. Shape changes arise in response to spatiotemporal gradients in cortical tension controlled by an intricate signalling network. Patterning of cortical tension is controlled by the activity of RhoGTPases, which are key regulators of the cytoskeleton and contractility. They are regulated by a diverse set of RhoGEFs/RhoGAPs, and spatiotemporal recruitment of these to the membrane patterns the tension gradients. We do not know why multiple RhoGEFs and RhoGAPs overlap spatially and temporally to control furrow formation and ingression. While we know that furrow ingression necessitates an increase in myosin contractility and a reorganisation of the cortex, we do not know how each RhoGEF/GAP contributes to these events. My overall goal is to determine how spatiotemporal recruitment of RhoGEFs/GAPs controls cell mechanics to drive shape change during furrowing. First, the molecular, structural and mechanical changes during furrowing will be characterised. Molecular and mechanical changes induced by each RhoGEF/GAP participating in furrowing will be investigated. Then, the interplay of RhoGEFs/ GAPs will be examined.I will use a combination of optical live and super-resolution microscopy and Atomic force microscopy to investigate structural and mechanical changes. To determine the role of each RhoGEF/GAP, I will design optogenetic actuators that enable spatiotemporal control of signalling. By combining two actuators, I will investigate the interplay between RhoGEFs/GAPs. I will use the results as input parameters for computational modelling of cell shape change based on the spatiotemporal localisation of signalling.