THE TAT PROTEIN OF EQUINE INFECTIOUS-ANEMIA VIRUS (EIAV) ACTIVATES CELLULAR GENE-EXPRESSION BY READ-THROUGH TRANSCRIPTION

The Tat protein of equine infectious anemia virus, EIAV, was shown to augment viral gene expression, presumably through interaction with the Tat responsive element, TAR. Recently, cell-free polyadenylation assa ys suggested that perturbation of the EIAV TAR secondary structure dim inished polyadenylation efficiency. The present study indicates that t he EIAV TAR regulates the efficiency of the 3'-end processing of viral RNA also in transfected cells. Moreover, our data suggest that the pr ovision of the EIAV Tat protein in trans potentiates read-through tran scription through the 3' viral long terminal repeat (3' LTR), thus sug gesting activation of downstream-located cellular genes. (C) 1998 Else vier Science B.V. All rights reserved.