Photo-ANA enables profiling of host-bacteria protein interactions during infection

Bacterial pathogens rapidly change and adapt their proteome to cope with the environment in host cells and secrete effector proteins to hijack host targets and ensure their survival and proliferation during infection. Excessive host proteins make it difficult to profile pathogens' proteome dynamics by conventional proteomics. It is even more challenging to map pathogen-host protein-protein interactions in real time, given the low abundance of bacterial effectors and weak and transient interactions in which they may be involved. Here we report a method for selectively labeling bacterial proteomes using a bifunctional amino acid, photo-ANA, equipped with a bio-orthogonal handle and a photoreactive warhead, which enables simultaneous analysis of bacterial proteome reprogramming and pathogen-host protein interactions of Salmonellaenterica serovar Typhimurium (S. Typhimurium) during infection. Using photo-ANA, we identified FLOT1/2 as host interactors of S. Typhimurium effector PipB2 in late-stage infection and globally profiled the extensive interactions between host proteins and pathogens during infection.

Automated summary

Bacterial pathogens adapt their proteome to survive in host cells and secrete effector proteins to manipulate host targets. Conventional proteomics struggles to profile pathogen proteome dynamics due to excessive host proteins. Mapping pathogen-host protein-protein interactions is challenging due to low abundance and transient interactions of bacterial effectors. A new method using a bifunctional amino acid, photo-ANA, allows selective labeling of bacterial proteomes and simultaneous analysis of proteome reprogramming and pathogen-host interactions during Salmonella infection.