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Genetic Incorporation of Biosynthesized L-dihydroxyphenylalanine DOPA and Its Application to Protein Conjugation
Published on: August 24, 2018
Using a quadruplet codon to expand the genetic code of an animal
Zhiyan Xi1, Lloyd Davis1, Kieran Baxter1
1Centre for Discovery Brain Sciences, University of Edinburgh, UK.
Abstract:
Genetic code expansion in multicellular organisms is currently limited to the use of repurposed amber stop codons. Here, we introduce a system for the use of quadruplet codons to direct incorporation of non-canonical amino acids in vivo in an animal, the nematode worm Caenorhabditis elegans. We develop hybrid pyrrolysyl tRNA variants to incorporate non-canonical amino acids in response to the quadruplet codon UAGA. We demonstrate the efficiency of the quadruplet decoding system by incorporating photocaged amino acids into two proteins widely used as genetic tools. We use photocaged lysine to express photocaged Cre recombinase for the optical control of gene expression and photocaged cysteine to express photo-activatable caspase for light inducible cell ablation. Our approach will facilitate the routine adoption of quadruplet decoding for genetic code expansion in eukaryotic cells and multicellular organisms.
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