Regulating Actin Assembly Microstructure through Cross-linkers

Actin networks are cytoskeletal materials responsible for controlling cell shape and providing a mechanical scaffold. Within the cell, these networks have a variety of distinct microstructures mediated by protein cross-linkers. These physiological cross-linkers have actin binding domains but differ in structural features, such as length and flexibility. Since there are a limited number of distinct physiological cross-linkers, systematically studying the relationship between the cross-linker and actin assembly microstructure remains challenging. We synthesize a cross-linker with a segment of DNA that connects two actin-binding sites (Lorenz et al., Adv. Mater., 2018). We change the length of the cross-linker systematically by changing the length of the DNA segment. We investigate actin assembly microstructures as a function of cross-linker length using fluorescence and transmission electron microscopy. This research will allow us to understand further how to regulate the mechanics and microstructure of bundles and networks through crosslinking of soft materials.