Acetylated Tat associates with a chromatinized HIV-1 promoter at or near nuc-1 but not nuc-1. A) Diagram of nucleosomes positioned on the integrated HIV-1 genome. The transcription start site is indicated as +1. Critical transcription factor binding sites (NF-κB, Sp1, and TBP) are indicated. Location of nuc-0 through nuc-4 are indicated above the diagram. B) ChIP analysis of the HIV-1 genome. The ChIP assay was performed as described [110, 111] with modifications (see Materials and Methods). HLM-1 cells (Tat-)  were transfected with the pCEP4/eTat vector  or no DNA and ChIP analysis was performed with anti- acetyl Tat 50/51 antibodies, anti-acetyl Tat 41 antibodies, or anti-acetyl H4 antibodies (positive control for acetylation of histones and association of nucleosomes with the HIV-1 promoter). The PCR primer pair location and expected sizes are indicated next to the expected amplified PCR products.