Novel monoclonal antibodies that differentiate between the binding of pp60c-src or protein phosphatase 2A by polyomavirus middle T antigen.
AUTOR(ES)
Dilworth, S M
RESUMO
Fourteen pGEX plasmids that express defined regions of polyomavirus middle T antigen in bacteria have been constructed. These polypeptides have been used to generate 18 new monoclonal antibodies directed against the unique portion of middle T and to map the approximate position of the antibody recognition sites onto the protein sequence. All of the antibodies effectively immunoprecipitate middle T and the associated 60- and 35-kDa components of protein phosphatase 2A. Four of the antibodies, however, do not react with middle T when it is bound to pp60c-src. These four probably bind to amino acids 203 to 218 of the middle T protein sequence, which are encoded by the mRNA immediately 3' to the splice junction that creates the C-terminal unique region. This suggests that additional middle T sequences are required for middle T's interaction with pp60c-src than are needed for its binding to protein phosphatase 2A. The antibodies localize this extra region and provide a means of distinguishing between these two associations.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=240352Documentos Relacionados
- Activation of the pp60c-src kinase by middle T antigen binding or by dephosphorylation.
- Catalytically Inactive Protein Phosphatase 2A Can Bind to Polyomavirus Middle Tumor Antigen and Support Complex Formation with pp60c-src
- Myristylation of pp60c-src is not required for complex formation with polyomavirus middle-T antigen.
- Altered sites of tyrosine phosphorylation in pp60c-src associated with polyomavirus middle tumor antigen.
- Simultaneous overexpression of avian pp60c-src and polyomavirus middle T antigen in mammalian cells.