Liu et al. (2020). Frontiers in Molecular Biosciences. doi: 10.3389/fmolb.2020.610277
…for studying cytoskeleton-membrane interactions and cellular shape changes. MATERIALS AND METHODS Preparation of Proteins and Reagents We purified actin from rabbit skeletal muscle acetone powder (Pel-Freez Biologicals) as described previously (Pardee and Aspudich, 1982) or purchased it from Cytoskeleton Inc, United States. ATTO 488 actin was purchased from Hypermol Inc, Germany. α-Actinin was purchased from…
Abstract
Depending on the physical and biochemical properties of actin-binding proteins, actin networks form different types of membrane protrusions at the cell periphery. Actin crosslinkers, which facilitate the interaction of actin filaments with one another, are pivotal in determining the mechanical properties and protrusive behavior of actin networks. Short crosslinkers such as fascin bundle F-actin to form rigid spiky filopodial protrusions. By encapsulation of fascin and actin in giant unilamellar vesicles (GUVs), we show that fascin-actin bundles cause various GUV shape changes by forming bundle networks or straight single bundles depending on GUV size and fascin concentration. We also show that the presence of a long crosslinker, α-actinin, impacts fascin-induced GUV shape changes and significantly impairs the formation of filopodia-like protrusions. Actin bundle-induced GUV shape changes are confirmed by light-induced disassembly of actin bundles leading to the reversal of GUV shape. Our study contributes to advancing the design of shape-changing minimal cells for better characterization of the interaction between lipid bilayer membranes and actin cytoskeleton.