The mapping of interferon-induced proteins and phosphoproteins from HeLa S3 cells.
Fourteen of 18 proteins induced by interferon-alpha (IFN-alpha) in HeLa S3 cells were labeled with [35S]methionine, resolved by two-dimensional electrophoresis, and assigned coordinates corresponding to HeLa proteins previously mapped by Bravo and Celis (Clin. Chem. 28, 766-781, 1982). Proteins phosphorylated with [gamma-32P]ATP in response to polyinosinic:polycytidylic acid [poly(I):poly(C)] were mapped similarly. Multiple phosphorylated species of a 72-kD protein were labeled in response to poly(I):poly(C) by extracts from IFN-treated cells but not by extracts from control cells. These are likely phosphorylated forms of the IFN-induced poly(I):poly(C)-dependent protein kinase, the enzyme responsible for the phosphorylation of the alpha-subunit of eukaryotic initiation factor 2 (eIF-2 alpha). Two phosphorylated forms of eIF-2 alpha were labeled in extracts of IFN-treated cells. One of these is a new phosphorylated product of the double-stranded (ds) RNA-activated protein kinase.
Higgins
D J
DJ
Department of Biochemistry, University of Iowa, Iowa City 52242.
Conway
T W
TW
D015180:Electrophoresis, Gel, Two-Dimensional; D006367:HeLa Cells; D006801:Humans; D007370:Interferon Type I / Q000494:pharmacology*; D010750:Phosphoproteins / Q000032:analysis* / Q000096:biosynthesis; D010766:Phosphorylation; D014176:Protein Biosynthesis; D011506:Proteins / Q000032:analysis*
D007370:Interferon Type I; D010750:Phosphoproteins; D011506:Proteins