(Link-Sign-Mech-Furr) Linking Signalling to Mechanics and Shape Changes in Mitotic Furrowing
Lead Research Organisation:
UNIVERSITY COLLEGE LONDON
Department Name: London Centre for Nanotechnology
Abstract
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.
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.
People |
ORCID iD |
| Guillaume Charras (Principal Investigator) | |
| Andreas Weber (Fellow) |
| Description | During cell division, a contractile ring forms for scission of the mother cell into two daughter cells. While it is generally thought that this ring assembles at anaphase, we show that the ring assembles much later. We show that two separate signalling pathways are necessary: one to recruit myosins and the other to organise filaments into a ring. We have generated optogenetic actuators to artificially activate each part of the control systems for |
| Exploitation Route | Cell division is central to life. When it is mysregulated, it can lead to cancer. Understanding the basis of cell division therefore allows to identify druggable targets for therapies. |
| Sectors | Pharmaceuticals and Medical Biotechnology |
| Description | The role of signalling in mitotic shape change |
| Organisation | University of Cambridge |
| Department | Department of Physiology, Development and Neuroscience |
| Country | United Kingdom |
| Sector | Academic/University |
| PI Contribution | Mitotic shape change is due to patterned signalling. At the cleavage furrow, multiple rhoGEFs and rhoGAPs participate to shape change. We have shown that depletion of these proteins alters shape change and mechanics. We are now using optogenetic constructs to dissect the exact contributions of each signalling protein. |
| Collaborator Contribution | One result of signalling is the creation of a contractile ring. Our Cambridge collaborators have developed approaches to image individual myosin mini-filaments and their orientation. These approaches allow a molecular view of the outcome of signalling, which is complementary to the mechanical signature that we can bring. Our Geneva collaborators have developed models to predict cell shape change from the knowledge of where optogenetic signalling is targeted. |
| Impact | This collaboration has given rise to a collaborative grant application. |
| Start Year | 2024 |
| Description | The role of signalling in mitotic shape change |
| Organisation | University of Geneva |
| Department | Physics Section |
| Country | Switzerland |
| Sector | Academic/University |
| PI Contribution | Mitotic shape change is due to patterned signalling. At the cleavage furrow, multiple rhoGEFs and rhoGAPs participate to shape change. We have shown that depletion of these proteins alters shape change and mechanics. We are now using optogenetic constructs to dissect the exact contributions of each signalling protein. |
| Collaborator Contribution | One result of signalling is the creation of a contractile ring. Our Cambridge collaborators have developed approaches to image individual myosin mini-filaments and their orientation. These approaches allow a molecular view of the outcome of signalling, which is complementary to the mechanical signature that we can bring. Our Geneva collaborators have developed models to predict cell shape change from the knowledge of where optogenetic signalling is targeted. |
| Impact | This collaboration has given rise to a collaborative grant application. |
| Start Year | 2024 |