RT Journal Article SR Electronic(1) A1 Maunders, Michelle J. A1 Petti, Lisa A1 Rowe, MartinYR 1994 T1 Precipitation of the Epstein—Barr virus protein EBNA 2 by an EBNA 3c-specific monoclonal antibody JF Journal of General Virology, VO 75 IS 4 SP 769 OP 778 DO https://doi.org/10.1099/0022-1317-75-4-769 PB Microbiology Society, SN 1465-2099, AB Two monoclonal antibodies, E3cD8 and E3cA10, were generated to the EBNA 3 c nuclear protein from the B95.8 isolate of Epstein-Barr virus (EBV). Both antibodies efficiently precipitate EBNA 3c from B95.8- transformed lymphoblastoid cell lines, and E3cA10 also detects EBNA 3c on Western blots. Whereas E3cD8 reacts with all 11 Type-1 isolates of EBV tested, and E3cA10 reacts with 14 of 17 Type-1 isolates, neither antibody detects the EBNA 3 c protein encoded by Type-2 isolates. E3cD8 recognizes a peptide sequence (PA/pPQAPYQGY) in a repeat region of the B95.8 EBNA 3c coding sequence which is not present in the prototype Type-2 AG876 sequence. The E3cA10 antibody epitope has been mapped to the minimal five amino acid B95.8 peptide, WAPSV, which has an alanine to valine substitution in the AG876 virus isolate. This substitution was also found in three Type-1 EBV isolates that expressed EBNA 3c proteins not detected by E3cA10. In immunoprecipitation studies E3cA10 additionally coprecipitated the EBNA 2 protein from Type-1 isolates of EBV. The possibility of a direct interaction between EBNA 2 and EBNA 3 c was ruled out by the demonstration that the antibody precipitated EBNA 2 from the Raji cell line which carries a virus with a deleted EBNA 3c gene. Since the WAPSV epitope identified in EBNA 3c is not present in EBNA 2, and no EBNA 2 linear peptide reactivity was detected in ELISA, it seems likely that E3cA10 recognizes a conformational epitope on EBNA 2. However, from the present data we cannot exclude the possibility that the antibody reacts with a cellular protein that physically associates with EBNA 2., UL https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-75-4-769