Open AccessTumor antigen(s) in cells productively infected by wild-type polyoma virus and mutant NG-18
Author(s) -
Brian Schaffhausen,
Jonathan Silver,
Thomas L. Benjamin
Publication year - 1978
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.75.1.79
Subject(s) - mutant , biology , microbiology and biotechnology , polyacrylamide gel electrophoresis , gel electrophoresis , antiserum , molecular mass , wild type , sodium dodecyl sulfate , antigen , virus , immunoprecipitation , sepharose , biochemistry , virology , gene , enzyme , genetics
When isolated by means of an anti-polyoma tumor (T) antiserum, the major product from mouse cells productively infected by wild-type polyoma virus is a polypeptide of 100,000 apparent molecular weight as judged by sodium dodecyl sulfate/polyacrylamide gel electrophoresis. In cells infected by NG-18, anhr-t mutant carrying a deletion of about 150 base pairs in the early region of the viral DNA, a T antigen species appears that comigrates with that of the wild-type virus. Comparisons of peptides after partial proteolysis reveal no differences between mutant and wild-type products. Both wild-type and mutant 100,000 products can be labeledin vivo with [32 P]orthophosphate. An independent and more reliable estimate of the molecular weight of this protein using guanidine/Sepharose chromatography yields a value of 81,000 for both mutant and wild-type species. The apparent identity of wild-type and mutant products indicates that the deletion in NG-18 lies outside of the region encoding this major T antigen species.Immunoprecipitates from wild-type infected cells shows four bands in addition to the “100,000” band; these have apparent molecular weights of 63,000, 56,000, 36,000, and 22,000 by sodium dodecyl sulfate/polyacrylamide gel electrophoresis; the 56,000 and 36,000 species are phosphorylated. All four of these lower molecular weight bands are absent or drastically reduced in the immunoprecipitates from NG-18-infected cells.