Synthetic Organelles for Multiple mRNA Selective Genetic Code Expansions in Eukaryotes.

Engineering new functionalities into living eukaryotic systems is one of the main goals of synthetic biology. To this end, often enzyme evolution or de novo protein design is employed, which each have their own advantages and disadvantages. As complimentary tools, we recently developed orthogonally translating and film-like synthetic organelles that allow to create new enzyme functionalities based on spatial separation. We applied this technology to genetic code expansion (GCE) and showed that it is possible to equip eukaryotic cells with multiple orthogonal genetic codes that enable the specific reprogramming of distinct translational machineries, each with single-residue precision.In this protocol, we describe how synthetic organelles can be used to perform mRNA selective GCE and how they can be further developed to allow the simultaneous incorporation of distinct noncanonical amino acids (ncAAs) into selected proteins and how this can be used to label proteins selectively with fluorescent dyes via bioorthogonal chemistry.