FIG. 4.

Tryptic phosphopeptide analyses of wild-type NS1 and cytoplasmic NS1 variant dl158. (A) Schematic pattern. (B and C) Peptide analyses. Wild-type NS1 (B) and mutant dl158 (C) were expressed by means of recombinant vaccinia viruses in A9 cells, metabolically ³²P labeled, and purified by immunoprecipitation and SDS-PAGE. Tryptic phosphopeptide maps were obtained by two-dimensional thin-layer electrophoresis and chromatography and were revealed by autoradiography. Arrows indicate a spot that was significantly reduced in intensity in the dl158 map and that was previously assigned to NS1 peptides harboring the phosphorylation sites T435 and S473 (7, 12), as indicated by filled dots in the schematic pattern.