Characterization of polyoma virus early proteins expressed from vaccinia virus recombinants.
We previously reported that live recombinant vaccinia viruses (VV) encoding either the large T (LT) or middle T (MT) antigens of polyoma virus (PyV) were able to induce rejection of tumors caused by PyV-transformed cells [Lathe et al., Nature 326 (1987) 878-880]. Here we present evidence that PyV early proteins expressed by the recombinants retain the biochemical characteristics of their authentic counterparts despite the cytopathic effect of VV infection. VV-encoded LT is a nuclear phosphoprotein, with specific DNA binding, ATPase and nucleotide-binding activities. VV-expressed MT associates with cellular kinases, particularly with pp60c-src, by which it is phosphorylated in vitro. Expression levels of LT and MT reached 10(6) molecules per infected cell. The use of VV as a vector is encouraged by the high expression level obtained and because VV infection does not seem to prevent appropriate post-translational processing of proteins encoded by VV recombinants.
Guizani
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INSERM U273, Centre de Biochimie du CNRS, Campus Valrose, Nice, France.
Kieny
M P
MP
Lathe
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Clertant
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P
D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism; D000818:Animals; D000952:Antigens, Polyomavirus Transforming / Q000235:genetics*; D015153:Blotting, Western; D002460:Cell Line; D002472:Cell Transformation, Viral; D005455:Fluorescent Antibody Technique; D006801:Humans; D010766:Phosphorylation; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D011995:Recombination, Genetic; D014616:Vaccinia virus / Q000235:genetics*
D000952:Antigens, Polyomavirus Transforming; D011494:Protein Kinases; D000251:Adenosine Triphosphatases