title: Mapping of a phosphorylation site in the 176R (19 kDa) early region 1B protein of human adenovirus type 5.
abstract: The 176-residue (176R) early region 1B (E1B) protein of human adenovirus type 5 (Ad5) was shown to be phosphorylated at serine in lytically infected KB cells at a level estimated to be about one phosphate group per 28 176R molecules. Through the analysis of peptides generated by cleavage with cyanogen bromide and Staphylococcus aureus V-8 protease the phosphorylation site was mapped to Ser-164. Using site-directed mutagenesis, a mutant was produced in which the codon for Ser-164 was changed to that of asparagine while leaving the coding sequence for the overlapping 496R protein unchanged. This virus, which replicated well on human KB cells, produced normal levels of 176R, but in an unphosphorylated form. The mutant transformed baby rat kidney cells in cooperation with E1A at an efficiency about one-half that obtained with wt E1B. These data therefore gave little indication that phosphorylation is essential for the function of 176R.
authors.affiliation: Department of Pathology, McMaster University, Hamilton, Ontario, Canada.
authors.forename: C J
authors.initials: CJ
authors.lastname: McGlade
authors.forename: M L
authors.initials: ML
authors.lastname: Tremblay
authors.forename: P E
authors.initials: PE
authors.lastname: Branton
mesh_terms: D017456:Adenovirus Early Proteins; D000260:Adenoviruses, Human / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002478:Cells, Cultured; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D009856:Oncogene Proteins, Viral / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D010957:Plasmids; D011233:Precipitin Tests; D051381:Rats; D015183:Restriction Mapping
chemical_list: D017456:Adenovirus Early Proteins; D009856:Oncogene Proteins, Viral