The simian immunodeficiency virus (SIV) rev gene regulates env expression.

The rev gene product is a trans-acting nuclear regulatory protein that is essential for AIDS virus replication. To define the effect of the SIV rev gene on its gp160 expression, two SV40 constructs have been made: pBC17 is a rev+env+ construct, and pBD21 is a rev-env+ construct. After transfecting the constructs into COS-1 cells, RNA, protein, syncytium formation, and monoclonal antibody blocking assays were performed. The results indicated that the SIV rev gene positively influenced the level of full-length env mRNA and was required for expression of SIV gp160.