Abstract
Epstein-Barr virus (EBV) latent membrane protein 2A (LMP2A) is expressed on the membrane of B-lymphocytes and blocks B cell receptor (BCR) signaling in EBV-transformed B-lymphocytes in vitro. The LMP2A amino-terminal domain, which is essential for the LMP2A-mediated block of B cell signal transduction, contains eight tyrosine residues. Three of these tyrosine residues (Y74, Y85, and Y112) have been demonstrated to be essential for the LMP2A-mediated block on protein tyrosine phosphorylation, calcium mobilization, and induction of BZLF1 expression after BCR activation. To investigate the importance of tyrosines at positions 60, 64, and 101 on B cell signaling, EBV recombinants were constructed containing a tyrosine-to- phenylalanine point mutation at amino acid 60, 64, or 101 within LMP2A. Tyrosine phosphorylation, calcium mobilization, and induction of BZLF1 expression were not affected by any of the tyrosine point mutations after BCR activation. In addition, constitutive phosphorylation of LMP2A was unaffected by any of the tyrosine point mutations. These data indicate that tyrosines 60, 64, and 101 are not essential for the LMP2A-mediated block of B cell signal transduction in transformed cell lines.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 485-495 |
| Number of pages | 11 |
| Journal | Virology |
| Volume | 263 |
| Issue number | 2 |
| DOIs | |
| State | Published - Oct 25 1999 |
Funding
We would like to thank the Longnecker and Spear Laboratories for providing invaluable advise and Lawrence Young for providing the BZ1 monoclonal antibody. R.S. was supported by National Institute of General Medical Sciences Grant (1F31-GM1956901) from the National Institutes of Health. R.L. is a scholar of the Leukemia Society of America and supported by U.S. Public Health Service Grants CA62234 and CA73507 from the National Cancer Institute.
ASJC Scopus subject areas
- Virology