IMMUNOLOGICAL IDENTIFICATION OF TACARIBE VIRUS PROTEINS

Tacaribe virus (TV), an arenavirus, is an enveloped virus with genetic information encoded in two segments of single-stranded RNA. The compl eted sequence of TV led to the identification of four open reading fra mes (ORF). In order to establish a direct link between ORFs in the seq uence of TV and proteins present in virus particles and virus-infected cells, segments of the molecularly cloned TV genome were engineered s o as to be expressed in Escherichia coli to produce fusion proteins th at were used to raise antisera. The antisera were in turn employed to identify the TV gene products. Serum to the putative nucleocapsid (N) protein reacted with a 68-kDa protein, both in TV particles and in the infected cells. Sera raised to the glycoprotein precursor (GPC) immun oprecipitated two proteins of 68 and 70 kDa from infected cell lysates . Analysis of GPC synthesis in the presence of tunicamycin revealed th at the unglycosylated GPC appeared as two polypeptides of 43 and 46 kD a. The putative RNA polymerase gene product (L) was detected as a appr oximate to 240-kDa protein. Serum to the small zinc-binding domain pro tein (p11-Z) recognized a protein of approximate to 11 kDa, Immunologi cal evidence is presented that in addition to N and L,two glycoprotein s (GP1 and GP2) and p11-Z are structural components of Tacaribe virion s.