Cell-selective labeling of bacterial proteomes with an orthogonal phenylalanine amino acid reporter

摘要

Orthogonal amino acid reporters allow the selective labeling of different cell types in heterogeneous populations through the expression of engineered aminoacyl tRNA synthetases. Here, we demonstrate that pra-ethynylphenylalanine (PEP) can be used as an orthogonal amino acid reporter for efficient selective labeling of an intracellular bacterial pathogen during infection. Radiolabeled or stable isotope-labeled amino acids, coupled with mass spectrometry, allow the differentiation of newly synthesized from pre-existing proteins. Nonetheless, it is still challenging to analyze changes in protein expression of individual cell types from heterogeneous populations since these labeled amino acids are incorporated into all proteomes.