Abstract
The art gene product of the human immunodeficiency virus is required for the expression of virion capsid and envelope gene proteins. The experiments presented here show that sequences located within the coding region of the envelope gene exert a negative effect on the expression of heterologous genes and that the negative effect of these sequences can be relieved by the art gene product. This region in the env gene contains negative regulatory sequences that inhibit gene expression, as well as a sequence necessary for the art gene product-dependent relief of repression. The experiments define the cis- and trans-acting components of a regulatory system that permits differential expression of human immunodeficiency virus virion structural and regulatory proteins.