Adenovirus early region proteins, ElA, E1B-55K, E4orf3 and E4orf6 regulate host cell processes to facilitate viral replication. E4orf3 suppress host cell anti-viral activities through association with host cell proteins in E4orf3 nuclear-track structures, whilst E1B-55K, E4orf3 and E4orf6 are all recruited to viral replication centres during infection to promote viral DNA replication and inhibit host cell antiviral activities. Immunoprecipitation coupled to mass spectrometry identified Toplla as an Ad12 E4orf3-binding protein that localized with E4orf3 in adenovirus-infected cells. It was determined that Toplla expression was induced during infection, and that Toplla was required for the adenovirusdependent stabilization of p53. It was also established that, despite their ability to cooperate functionally, Toplla and p53 do not associate physically during infection. Immunoprecipitation coupled to mass spectrometry was also used to identify host cell proteins recruited to viral replication centres during adenovirus infection. The RP A-1 binding protein, Smarcall, and the FACT complex histone chaperone protein, SSRPl were identified as host cell proteins recruited to viral replication centres during infection. Following recruitment to viral replication centres Smarcall was found to be degraded in an E1B-55K and E4orf6 dependent manner, whilst SSRPl was found to be stable during infection and was not targeted for degradation.