Identification of a protein encoded by the vpu gene of HIV-1

Abstract

Human immunodeficiency virus 1 (HIV-1) is the aetiological agent of AIDS^1–3. The virus establishes lytic, latent and non-cytopathic productive infection in cells in culture^4,5. The complexity of virus‐host cell interaction is reflected in the complex organization of the viral genome^6–9. In addition to the genes that encode the virion capsid and envelope proteins and the enzymes required for proviral synthesis and integration common to all retroviruses, HIV-1 is known to encode at least four additional proteins that regulate virus replication, the tat, art, sor and 3′ orf proteins, as well as a protein of unknown function from the open reading frame called R^10–18. Close examination of the nucleic acid sequences of the genomes of multiple HIV isolates raised the possibility that the virus encodes a previously undetected additional protein. Here we report that HIV-1 encodes a ninth protein and that antibodies to this protein are detected in the sera of people infected with HIV-1. This protein distinguishes HIV-1 isolates from the other human and simian immunodeficiency viruses (HIV-2 and SIV)^19–21 that do not have the capacity to encode a similar protein.