Insertion-Ligation Reconstitution of Transmembrane Proteins for Functional Interfaces in Synthetic Cells.

In living cells, transmembrane (TM) proteins transduce extracellular cues across a lipid bilayer, a structure that is otherwise impermeable to high-molecular weight and charged molecules. Synthetic cells (SCs), lipid bilayer-based systems that offer complete control over composition and response, have emerged as attractive candidates for programmable transduction in biomedicine, sensing, and computing applications. However, SCs lack the complex machinery native to living cells that insert TM proteins into lipid membranes, limiting their potential for extracellular-to-intracellular transduction. Here, we present a two-step chemical method to reconstitute functional single-pass TM proteins in SCs, termed insertion-ligation. Using the insertion-ligation approach, we report reconstitution of SC-SC interfaces that transduce extracellular adhesion activity into intracellular organization and transmembrane complexes capable of signal transduction across the bilayer. Our chemical strategy enables the reconstitution of any single-pass TM protein in SCs, allowing researchers to access this functionally diverse class of proteins without the need for insertion machinery.