EXPRESSION OF THE HUMAN FOAMY VIRUS BEL-1 TRANSACTIVATOR IN INSECT CELLS

The human foamy virus (HFV) bel-1 transactivator protein was expressed in insect cells by a recombinant baculovirus. For the generation of t he recombinant baculovirus, Acbel-1, the bel-1 gene of an HFV mutant w as used, that bears truncations in the bel-1 overlapping bel-2 open re ading frame. Acbel-1 infected Sf9 cells produced high amounts of recom binant protein of the same electrophoretic mobility (36 kD) as bel-1 e xpressed in mammalian cells. The baculovirus expressed bel-1 protein w as readily identified by a polyclonal rabbit serum directed against be l-I in immunoblot assay. As in mammalian cells, bel-1 was predominantl y localized to the nucleus of Acbel-1 infected insect cells. The bacul ovirus expressed bel-1 protein will be of use to determine the action of this novel viral transactivator more precisely.