Cell-dependent function of HIV-1 Vif for virus replication (Review).

It has been well established that the Vif protein of human immunodeficiency virus type 1 (HIV-1) acts late in the viral life cycle and increases the infectivity of the progeny virions in a producer cell-dependent manner. The virions produced in the absence of Vif in non-permissive cells (Delta Vif) are defective for a step(s) before and/or during reverse transcription. In this review, the functional and structural analyses of these virions including our new data are summarized.