Post-transcriptional regulation accounts for the trans-activation of the human T-lymphotropic virus type III.

The level of synthesis of viral proteins and heterologous proteins under the control of long terminal repeat sequences of human T-lymphotropic virus type III (HTLV-III or LAV) increases dramatically in cells that constitutively express the HTLV-III trans-activator protein. Increased levels of protein synthesis occur without a comparable increase in the levels of corresponding messenger RNA. We propose that post-transcriptional events mediated by the HTLV-III trans-activator protein account for positive regulation of HTLV-III gene products in infected cells.