FIG 3.

The N-terminal domain of SUN1 is required for its inhibition of HIV-1 infection. (A) Schematic representation of SUN1 and its truncation mutants. (B and C) Plasmids expressing Flag-tagged SUN1 or truncation mutants were transiently transfected into HEK293A cells together with plasmids expressing CD4 and CCR5. A plasmid expressing renilla luciferase was included to serve as a control. At 48 h posttransfection, cells were infected with AE-enveloped NL4-3luc. At 48 h postinfection, cells were lysed. (B) Luciferase activities were measured. Firefly luciferase activity was normalized to renilla luciferase activity. Data presented are means and SD for three independent experiments. (C) Expression of the SUN1 mutants was analyzed by Western blotting. The positions of the truncation mutants are indicated with asterisks. EV, empty vector.