Altered sites of tyrosine phosphorylation in pp60c-src associated with polyomavirus middle tumor antigen.
AUTOR(ES)
Cartwright, C A
RESUMO
We characterized the tyrosine phosphorylation sites of free pp60c-src and of pp60c-src associated with the polyomavirus middle tumor antigen (mT) in transformed avian and rodent cells. The sites of tyrosine phosphorylation in the two populations of pp60c-src were different, both in vitro and in vivo. Free pp60c-src was phosphorylated in vitro at a single site, tyrosine 416. pp60c-src associated with mT was phosphorylated in vitro on tyrosine 416 and on one or more additional tyrosine residues located in the amino-terminal region of the molecule. Free pp60c-src in polyomavirus mT-transformed cells was phosphorylated in vivo on tyrosine 527. In contrast, pp60c-src associated with mT was phosphorylated in vivo on tyrosine 416 and not detectably on tyrosine 527. Thus, the in vivo phosphorylation sites of pp60c-src associated with mT in transformed cells are identical to those of pp60v-src, the Rous sarcoma virus transforming protein. The results suggest that altered phosphorylation of pp60c-src associated with mT may play a role in the enhancement of the pp60c-src protein kinase activity and in cell transformation by polyomavirus.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=367682Documentos Relacionados
- Tyrosine phosphorylation within the amino-terminal domain of pp60c-src molecules associated with polyoma virus middle-sized tumor antigen.
- Myristylation of pp60c-src is not required for complex formation with polyomavirus middle-T antigen.
- Analysis of middle tumor antigen and pp60c-src interactions in polyomavirus-transformed rat cells.
- Regulation of pp60c-src and its interaction with polyomavirus middle T antigen in insect cells.
- Simultaneous overexpression of avian pp60c-src and polyomavirus middle T antigen in mammalian cells.
