Specific interaction of TFII-I with an upstream element on the HIV-1 LTR regulates induction of latent provirus

RBF-2 is a factor comprised of a USF1/2 heterodimer, whose association with a highly conserved upstream element (RBEIII) on the HIV-1 LTR requires a co-factor TFII-I. We have identified specific nucleotides, immediately 3' of RBEIII that are required for stable association of TFII-I with this region of the LTR. Mutations that inhibit interaction of TFII- I with DNA also prevent stimulation of USF binding to RBEIII, and render the integrated LTR unresponsive to T cell signaling. These results demonstrate an essential role of TFII- I bound at an upstream LTR element for viral replication. (C) 2008 Federation of European Biochemical Societies. Published by Elsevier B. V. All rights reserved.