DNA Origami Signaling Units Transduce Chemical and Mechanical Signals in Synthetic Cells

Abstract

Transmembrane proteins transmit chemical signals as well as mechanical cues. The latter is often achieved by coupling to the cytoskeleton. The incorporation of fully engineerable membrane-spanning structures for the transduction of chemical and, in particular, mechanical signals is therefore a critical aim for bottom-up synthetic biology. Here, a membrane-spanning DNA origami signaling units (DOSUs) is designed and mechanically coupled to DNA cytoskeletons encapsulated within giant unilamellar vesicles (GUVs). The incorporation of the DOSUs into the GUV membranes is verified and clustering upon external stimulation is achieved. Dye-influx assays reveal that clustering increases the insertion efficiency. The transmembrane-spanning DOSUs act as pores to allow for the transport of single-stranded DNA into the GUVs. This is employed to trigger the reconfiguration of DNA cytoskeletons within GUVs. In addition to chemical signaling, mechanical coupling of the DOSUs to the internal DNA cytoskeletons is induced. With chemical cues from the environment, clustering of the DOSUs is induced, which triggers a symmetry break in the organization of the DNA cytoskeleton inside of the GUV. DNA-based transmembrane structures are engineered that transduce signals without transporting the signaling molecule itself—providing a route toward signal processing and adaptive synthetic cells.