Figure 4

Phosphatase treatment alters the RT isoforms detected. H3B and Hut-78 cells were mixed and incubated at 37°C for 40 mins, cells were then lysed and virus protein immunoprecipitated using heat-inactivated AIDS patient antibody cross-linked to protein A sepharose beads. Immunoprecipitates were incubated without (A) or with (B) calf intestinal alkaline phosphatase (CIAP), proteins pelleted, washed and subjected to 2D gel electrophoresis on a pH 7–11 non-linear, 11 cm Immobiline DryStrip gel along with 3 μg of GAPDH protein, and then resolved by SDS-PAGE. RT was detected by Western blot using an anti-RT antibody. RT isoforms are designated by a black arrow and spots not routinely observed are indicated by a white arrow. Experiments were replicated (n = 3).