Time of Synthesis and Cellular Location of Epstein--Barr Virus-specified Polypeptides Radioimmunoprecipitated from Iododeoxyuridine-induced Burkitt Lymphoma/Somatic Cell Hybrids

Abstract

The Burkitt lymphoma/somatic cell hybrid D98/HR-1 contains repressed Epstein-Barr virus (EBV) genomes which can be induced by 5-iodo-2''-deoxyuridine (IdUrd) to express the EBV early antigen (EA) and the virus capsid antigen (VCA). Nuclear and cytoplasmic fractions prepared from uninduced, partially induced and fully induced hybrid cells were radioimmunoprecipitated with human sera having high antibody titers against EA and VCA. Three polypeptides, with MW 127 .times. 103, 115 .times. 103 and 84 .times. 103 (127K, 115K and 84K), were detected in cells induced to express EA. All 3 polypeptides continued to be synthesized late in infection. One of the polypeptides was predominantly nuclear, 1 predominantly cytoplasmic and 1 found in both fractions. Three polypeptides, with MW 144K, 137K and 50K, were detectable only in cells induced to express both EA and VCA. All 3 polypeptides were found predominantly in the nuclear fraction.