@article{mbs:/content/journal/jgv/10.1099/vir.0.000205, author = "Makadiya, Nirajkumar and Gaba, Amit and Tikoo, Suresh K.", title = "Cleavage of bovine adenovirus type 3 non-structural 100K protein by protease is required for nuclear localization in infected cells but is not essential for virus replication", journal= "Journal of General Virology", year = "2015", volume = "96", number = "9", pages = "2749-2763", doi = "https://doi.org/10.1099/vir.0.000205", url = "https://www.microbiologyresearch.org/content/journal/jgv/10.1099/vir.0.000205", publisher = "Microbiology Society", issn = "1465-2099", type = "Journal Article", abstract = "The L6 region of bovine adenovirus type 3 (BAdV-3) encodes a non-structural protein named 100K. Rabbit antiserum raised against BAdV-3 100K recognized a protein of 130 kDa at 12–24 h and proteins of 130, 100, 95 and 15 kDa at 36–48 h after BAdV-3 infection. The 100K species localized to the nucleus and the cytoplasm of BAdV-3-infected cells. In contrast, 100K localized predominantly to the cytoplasm of the transfected cells. However, BAdV-3 infection of cells transfected with 100K–enhanced yellow fluorescent protein-expressing plasmid detected fluorescent protein in the nucleus of the cells, suggesting that other viral proteins may be required for the nuclear localization of 100K. Interaction of BAdV-3 100K with BAdV-3 33K protein did not alter the cytoplasmic localization of 100K. However, co-expression of BAdV-3 100K and BAdV-3 protease localized 100K to the nucleolus of the transfected cells. Subsequent analysis suggested that BAdV-3 protease cleaves 100K at two identified potential protease cleavage sites (aa 740–745 and 781–786) in transfected or BAdV-3-infected cells. The cleaved C terminus (107 aa) was localized to the nucleolus of the transfected cells. Further analysis suggested that the cleaved C terminus contains a bipartite nuclear localization signal and utilizes import receptor importin-α3 of the classical importin-α/β transport pathway for nuclear transport. Successful isolation of recombinant BAdV-3 expressing mutant 100K (substitution of alanine for glycine in the potential protease cleavage site) suggested that cytoplasmic cleavage of BAdV-3 100K by adenoviral protease is not essential for virus replication.", }