The viral protein U (Vpu)-interacting host protein ATP6V0C down-regulates cell-surface expression of tetherin and thereby contributes to HIV-1 release — ATP6V0C is required for Vpu-mediated tetherin degradation — The viral protein U (Vpu)-interacting host protein ATP6V0C down-regulates cell-surface expression of tetherin and thereby contributes to HIV-1 release — ATP6V0C is required for Vpu-mediated tetherin degradation