J Virol. 1990 Jul;64(7):3407-16. Unique Identifier : AIDSLINE
Several lines of evidence are compatible with the hypothesis that
Epstein-Barr virus (EBV) nuclear antigen 2 (EBNA-2) or leader protein
(EBNA-LP) affects expression of the EBV latent infection membrane
protein LMP1. We now demonstrate the following. (i) Acute transfection
and expression of EBNA-2 under control of simian virus 40 or Moloney
murine leukemia virus promoters resulted in increased LMP1 expression in
P3HR-1-infected Burkitt's lymphoma cells and the P3HR-1 or Daudi cell
line. (ii) Transfection and expression of EBNA-LP alone had no effect on
LMP1 expression and did not act synergistically with EBNA-2 to affect
LMP1 expression. (iii) LMP1 expression in Daudi and P3HR-1-infected
cells was controlled at the mRNA level, and EBNA-2 expression in Daudi
cells increased LMP1 mRNA. (iv) No other EBV genes were required for
EBNA-2 transactivation of LMP1 since cotransfection of recombinant
EBNA-2 expression vectors and genomic LMP1 DNA fragments enhanced LMP1
expression in the EBV-negative B-lymphoma cell lines BJAB, Louckes, and
BL30. (v) An EBNA-2-responsive element was found within the -512 to +40
LMP1 DNA since this DNA linked to a chloramphenicol acetyltransferase
reporter gene was transactivated by cotransfection with an EBNA-2
expression vector. (vi) The EBV type 2 EBNA-2 transactivated LMP1 as
well as the EBV type 1 EBNA-2. (vii) Two deletions within the EBNA-2
gene which rendered EBV transformation incompetent did not transactivate
LMP1, whereas a transformation-competent EBNA-2 deletion mutant did
transactivate LMP1. LMP1 is a potent effector of B-lymphocyte activation
and can act synergistically with EBNA-2 to induce cellular CD23 gene
expression. Thus, EBNA-2 transactivation of LMP1 amplifies the
biological impact of EBNA-2 and underscores its central role in
EBV-induced growth transformation.
Antigens, Viral/*GENETICS/*PHYSIOLOGY B-Lymphocytes/*PHYSIOLOGY
Blotting, Western Cell Division Cell Transformation, Viral Cloning,
Molecular *Gene Expression Regulation, Viral Genes, Structural, Viral
Human In Vitro Regulatory Sequences, Nucleic Acid Support, Non-U.S.
Gov't Support, U.S. Gov't, P.H.S. Trans-Activators/*PHYSIOLOGY
JOURNAL ARTICLE