FIGURE 7.

SAMHD1 RXL mutants have decreased ability to form tetramers in cells. HEK293T cells were transfected with empty vector, HA-tagged SAMHD1 WT- (1 μg), or mutant-expressing constructs (10 μg), or with high levels of WT or F → W mutant-expressing plasmid DNA (10 μg) and then were treated with 1% formaldehyde for cross-linking (A) or not treated (B) the day following transfection. After a 10-min incubation at 37 °C, the cross-linking was stopped by the addition of glycine. The cell lysates were harvested, and monomeric and oligomeric SAMHD1 proteins were assessed by immunoblotting using anti-HA. Arrows denote monomer, dimer, trimer, and tetramer forms of SAMHD1 at the respective predicted molecular weights. The experiments were repeated three times, and one representative experiment is shown.