Mapping Host Proteins in Measles Virus Inclusion Bodies Using APEX2

Measles virus (MeV) replicates within cytoplasmic inclusion bodies (IBs) that recruit host proteins to facilitate viral replication. To identify these host factors, we employ APEX2, a proximity-labeling enzyme that biotinylates neighboring proteins, in combination with optogenetics to precisely target APEX2 to IBs in human lung cells. Biotinylated proteins are subsequently isolated and identified by mass spectrometry. By comparing the IB proteome throughout the course of infection, we aim to comprehensively map the host proteins that support MeV replication and gain insight into previously uncharacterized viral-host interactions.