Fig. 1

Interaction between HIV-1 IN, LEDGF/p75 and FACT complex. A Schematic representation of the previously reported interactions between HIV-1 IN, LEDGF/p75 and FACT complex is shown in a. IN/FACT, IN/LEDGF, LEDGF/FACT, IN/LEDGF/FACT and IN/IBD/FACT interactions were analyzed by co-immunoprecipitation using recombinant cofactors and polyclonal anti-HIV-1 IN antibodies. IBD/FACT interactions were analyzed by GST-pull down using IBD-GST and FACT recombinant proteins. The interactions were monitored either direct gel staining using colloidal blue or western blot using the corresponding antibodies and quantified by Image J software (see quantification in b and representative experiments in Additional file 3: Figure S3). All values are shown as the mean ± standard deviation (error bars) of at least three independent sets of experiments. The p-values were calculated by Student’s t test and are shown as *p < 0.05 and **p < 0.005 to represent the probability of obtaining significant differences compared with the data obtained with the negative background obtained with the beads alone. Cellular interaction between SSRP1, LEDGF/p75 and IN was checked by immunoprecipitation with an anti-FLAG antibodies in cells lysates obtained from LEDGF/p75-deficient cells (si1340/1428 cells) and transfected with plasmid expressing SSRP1-Myc and HIV-1 IN-Myc, and either FLAG-LEDGF/p75 (lane 1) or an empty plasmid (lane 2) (c). Then, immunoprecipitated proteins were evaluated for the presence of the expressed proteins by immunoblotting with tag-specific antibodies. (**) represents a longer exposure of (*). Detection of light chain Igs were used as loading control. The experiment was performed twice with identical results