eIF3m promotes fowl adenovirus serotype 4 replication via interacting with ORF1B protein.

Eukaryotic initiation factors (eIFs), a bunch of proteins that deeply involved in translation initiation of mRNA in eukaryotes, are closely associated with physiological and pathological processes. eIF3m, a core subunit in eIF3 complex, also played critical roles in virus infection. In this study, a co-immunoprecipitation coupled with mass spectrometry (Co-IP/MS) was performed to identify host factors that interacted with ORF1B, a unique non-structural protein of fowl adenovirus serotype 4 (FAdV-4). Among 2502 cellular proteins, eIF3m, especially its C-terminal part, was verified to interact with ORF1B and these two proteins co-localized in the cytoplasm. Importantly, overexpression of eIF3m promoted FAdV-4 replication in LMH cells, whereas knockdown eIF3m exerted an opposite effect. Collectively, these findings indicate that ORF1B hijacked eIF3m to positively participate in FAdV-4 infection.