Specific NF-κB subunits act in concert with tat to stimulate human immunodeficiency virus type 1 transcription

NF-κB is a protein complex which functions in concert with the tat-I gene product to stimulate human immunodeficiency virus (HIV) transcription. To determine whether specific members of the NF-κB family contribute to this effect, we have examined the abilities of different NF-κB subunits to act with Tat-I to stimulate transcription of HIV in Jurkat T-leukemia cells. We have found that the p49(100) DNA binding subunit, together with p65, can act in concert with Tat-I to stimulate the expression of HIV-CAT plasmid. Little effect was observed with 50-kDa forms of p105 NF-κB or rel, in combination with p65 or full-length c-rel, which do not stimulate the HIV enhancer in these cells. These findings suggest that the combination of p49(100) and p65 NF-κB can act in concert with the tat-I gene product to stimulate the synthesis of HIV RNA.