Time of synthesis and cellular location of Epstein-Barr virus-specified polypeptides radioimmunoprecipitated from iododeoxyuridine-induced Burkitt lymphoma/somatic cell hybrids.

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 titres against EA and VCA. Three polypeptides, with mol. wt. 127 x 10(3), 115 x 10(3) and 84 x 10(3) (127K, 115K and 84K), were detected in cells induced to express EA. All three polypeptides continued to be synthesized late in infection. One of the polypeptides was predominantly nuclear, one predominantly cytoplasmic, and one found in both fractions. Three polypeptides, with mol. wt. 144K, 137K and 50K, were detectable only in cells induced to express both EA and VCA. All three polypeptides were found predominantly in the nuclear fraction.