RT Journal Article
SR Electronic
T1 Rho and F-actin self-organize within an artificial cell cortex
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2021.04.09.438460
DO 10.1101/2021.04.09.438460
A1 Jennifer Landino
A1 Marcin Leda
A1 Ani Michaud
A1 Zachary T. Swider
A1 Mariah Prom
A1 Christine M. Field
A1 William M. Bement
A1 Anthony G. Vecchiarelli
A1 Andrew B. Goryachev
A1 Ann L. Miller
YR 2021
UL http://biorxiv.org/content/early/2021/04/10/2021.04.09.438460.abstract
AB The cell cortex, comprised of the plasma membrane and underlying cytoskeleton, undergoes dynamic reorganizations during a variety of essential biological processes including cell adhesion, cell migration, and cell division1,2. During cell division and cell locomotion, for example, waves of filamentous-actin (F-actin) assembly and disassembly develop in the cell cortex in a process termed “cortical excitability”3–7. In developing frog and starfish embryos, cortical excitability is generated through coupled positive and negative feedback, with rapid activation of Rho-mediated F-actin assembly followed in space and time by F-actin-dependent inhibition of Rho8,9. These feedback loops are proposed to serve as a mechanism for amplification of active Rho signaling at the cell equator to support furrowing during cytokinesis, while also maintaining flexibility for rapid error correction in response to movement of the mitotic spindle during chromosome segregation10. In this paper, we develop an artificial cortex based on Xenopus egg extract and supported lipid bilayers (SLBs), to investigate cortical Rho and F-actin dynamics11. This reconstituted system spontaneously develops two distinct dynamic patterns: singular excitable Rho and F-actin waves and non-traveling oscillatory Rho and F-actin patches. Both types of dynamic patterns have properties and dependencies similar to the cortical excitability previously characterized in vivo9. These findings directly support the longstanding speculation that the cell cortex is a self-organizing structure and present a novel approach for investigating mechanisms of Rho-GTPase-mediated cortical dynamics.HighlightsAn artificial cell cortex comprising Xenopus egg extract on a supported lipid bilayer self-organizes into complex, dynamic patterns of active Rho and F-actinWe identified two types of reconstituted cortical dynamics – excitable waves and coherent oscillationsReconstituted waves and oscillations require Rho activity and F-actin polymerizationCompeting Interest StatementThe authors have declared no competing interest.(F-actin)Filamentous actin(SLB)supported lipid bilayer(rGBD)Rho binding domain of Rhotekin(UtrCH)Utrophin calponin homology domain(TIRF)Total Internal Reflection Fluorescence(PI(4,5)P2)Phosphatidylinositol 4,5-bisphosphate(GAP)GTPase activating protein(GTP)Guanosine triphosphate