Identification of HIV-1 vpr Product and Function.Cohen, Eric A.; Terwilliger, Ernest F.; Jalinoos, Yassamin; Proulx, Jeffrey; Sodroski, Joseph G.; Haseltine, William A.Journal of Acquired Immune Deficiency Syndromes: January 1990 Article: PDF Only Abstract Summary: To investigate the role of vpr (viral protein R) in the replication and cytopathicity of human immunodeficiency virus type 1 (HIV-1), infectious proviruses were constructed that were isogenic except for the ability to produce the protein product of vpr. The experiments described here demonstrate that vpr encodes a 96 amino acid 15 kDa protein. The vpr product increases the rate of replication and accelerates the cytopathic effect of the virus in T cells. Vpr acts in trans to increase levels of viral protein expression. The stimulatory effect of vpr is observed to act on the HIV-1 LTR as well as on several heterologous promoters. (C) Lippincott-Raven Publishers.