Engineering ssRNA tile filaments for (dis)assembly and membrane binding

Abstract

Cytoskeletal protein filaments such as actin and microtubules confer mechanical support to cells and facilitate many cellular functions such as motility and division. Recent years have witnessed the development of a variety of molecular scaffolds that mimic such cytoskeletal filaments. Indeed, filaments that are programmable and compatible with biological systems may prove useful in studying or substituting such proteins. Here, we explore the use of ssRNA tiles to build and modify cytoskeletal-like filaments in vitro. We engineer a number of functionalities that are crucial to the function of natural cytoskeletal systems into the ssRNA tiles, including the abilities to assemble or disassemble filaments, to tune the filament stiffness, to induce membrane binding, and to attach binding proteins. The work paves the way for building dynamic cell-like cytoskeletal systems made out of rationally designed ssRNA tiles that can be transcribed in natural or synthetic cells.