Abstract
A protein, called tip, of herpesvirus saimiri associates with Lck in transformed T cells. To investigate the effects of complex formation on cellular signal transduction, we constructed human Jurkat-T-cell lines expressing tip. The expression of tip in Jurkat-T cells dramatically suppressed cellular tyrosine phosphorylation and surface expression of lymphocyte antigens. The expression of tip also blocked the induction of tyrosine phosphorylation by anti-CD3 stimulation. The expression of tip in fibroblast cells suppressed the transforming activity of oncogenic F505 Lck. Binding assays showed that the SH3 domain of Lck is sufficient to form a stable complex with tip in vitro. These results demonstrate that tip acts at an early stage of the T-cell signal transduction cascade by associating with Lck and downregulating Lck-mediated activation. Inhibition of Lck-mediated signal transduction by tip in T cells appears to be analogous to the inhibition of Lyn/Syk-mediated signal transduction in B cells by LMP2A of the B-cell-tropic Epstein-Barr virus.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 7814-7822 |
| Number of pages | 9 |
| Journal | Journal of virology |
| Volume | 69 |
| Issue number | 12 |
| DOIs | |
| State | Published - Dec 1995 |
| Externally published | Yes |
ASJC Scopus subject areas
- Microbiology
- Immunology
- Insect Science
- Virology