Temporal Proteomic and Phosphoproteomic Analysis of EV-A71-Infected Human Cells

Human enterovirus A71 (EV-A71), a member of the Picornaviridae
family, is one of the main etiological viruses that lead to hand,
foot, and mouth disease (HFMD). We utilized a multiplex tandem mass
tag-based quantitative proteomic technique to monitor the alternation
of the whole cell proteome and phosphoproteome of human rhabdomyosarcoma
cells over the course of EV-A71 infection. We successfully quantified
more than 7000 host proteins and 17,000 phosphosites, of which 80
proteins and nearly 1700 phosphosites were significantly regulated
upon viral infection. We found that Myc proto-oncogene protein level
decreased significantly, benefiting EV-A71 replication. Multiple signaling
pathways were regulated in phosphorylation events that converge for
protein translation, cell cycle control, and cell survival. Numerous
host factors targeted by virus proteins are phosphoproteins. These
factors are involved in host translational initiation, unfolded protein
response, endoplasmic reticulum stress, and stress granule formation,
and their phosphorylation may play key roles in the virus life cycle.
Notably, we identified three conserved phosphorylation sites on viral
polyproteins that have not been previously reported. Our study provides
valuable resources for a systematic understanding of the interaction
between the host cells and the EV-A71 at the protein and the post-translational
level.