FIG. 2.

Vpu accelerates the turnover of mature endogenous BST-2 in HeLa cells. (A) 293T cells were transfected with 1 μg of Bst-2, pulse-labeled for 30 min by the addition of ³⁵S-labeled amino acids, and chased for 30 min in complete medium. Mock represents untransfected cells labeled and immunoprecipitated in a similar manner. (B) HeLa cells were infected with pCMV-VSVg-pseudotyped pNL4-3 or pNL4-3/Udel virus along with 8 μg/μl polybrene. Twenty-four hours after infection cells were pulse-labeled for 1 h at 37°C by addition of ³⁵S-labeled amino acids and chased for the indicated time intervals in complete medium. BST-2 was immunoprecipitated with specific antibodies. A representative result is shown. The position of molecular weight standards is shown on the left. (C) The percentage of BST-2 remaining at each time point was calculated relative to the signal at time zero. (D and E) Total levels of BST-2 were calculated by adding both immature BST-2 (D) and mature BST-2 (E). Mature BST-2 and immature BST-2 are indicated on the right. Plotted data are derived from three independent experiments. Error bars represent standard errors of the means.