FIG. 3.

Coimmunoprecipitation of Vpu and CD74 from HIV-infected cells. U937 cells were infected with HIV-1 NL4-3 (Vpu⁺) or NL4-3U35 (Vpu⁻), and cell lysates were prepared at the indicated times postinfection. The lysates were then immunoprecipitated (IP) with anti-CD74 followed by Western blotting (WB) with anti-Vpu. The immunoprecipitated Vpu proteins are shown. Alternatively, infected cell lysates were directly Western blotted with anti-Vpu antibodies. As nonspecific controls, the same lysates were also immunoprecipitated with an isotype-matched anti-EGFR rabbit polyclonal antibody followed by Western blotting with either anti-Vpu or anti-EGFR antibody.