Association of protein phosphatase 2A with polyoma virus medium tumor antigen

Proc Natl Acad Sci U S A. 1990 Apr;87(7):2521-5. doi: 10.1073/pnas.87.7.2521.

Abstract

The polyoma virus medium and small tumor antigens, as well as simian virus 40 small tumor antigen, form specific complexes with two cellular proteins designated 61- and 37-kDa proteins. In this report, we demonstrate that the 61- and 37-kDa proteins correspond to the A and C subunits, respectively, of the serine- and threonine-specific protein phosphatase 2A (PP2A). On the one hand, antibodies raised against the 61-kDa protein reacted specifically with the purified A subunit of PP2A. Furthermore, the amino acid sequences of seven tryptic peptides from the A subunit were almost identical to sequences of the 61-kDa protein as deduced from the corresponding cDNA sequence. On the other hand, antibodies against the purified C subunit (catalytic subunit) of PP2A reacted specifically with the medium tumor antigen-associated 37-kDa protein. These data suggest a role of PP2A in cell transformation by polyoma virus and simian virus 40.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenoviruses, Human / enzymology
  • Adenoviruses, Human / genetics*
  • Adenoviruses, Human / immunology
  • Amino Acid Sequence
  • Antigens, Polyomavirus Transforming / analysis*
  • Antigens, Polyomavirus Transforming / immunology
  • Cell Line
  • Humans
  • Immunoblotting
  • Macromolecular Substances
  • Molecular Sequence Data
  • Molecular Weight
  • Phosphoprotein Phosphatases / analysis
  • Phosphoprotein Phosphatases / genetics*
  • Phosphoprotein Phosphatases / immunology
  • Protein Phosphatase 2
  • Sequence Homology, Nucleic Acid

Substances

  • Antigens, Polyomavirus Transforming
  • Macromolecular Substances
  • Phosphoprotein Phosphatases
  • Protein Phosphatase 2