CLEAVAGE OF GAG PRECURSOR IS REQUIRED FOR EARLY REPLICATION PHASE OF HIV-1

A mutant of human immunodeficiency virus type 1 (HIV-1), which is defi cient for Gag precursor cleavage and noninfectious, was characterized with respect to its defective step in the viral replication phase. Upo n transfection, the mutant produced a normal level of progeny virions as monitored by electron microscopy and RNA hybridization. Single-roun d replication assay demonstrated, in contrast, that the mutant was def ective at the early phase of the replication cycle. Furthermore, no vi ral DNA was detected in the cells infected with the mutant. Taken toge ther, it is concluded that maturation of Gag precursor protein of HIV- 1 is required for an early event(s) before or during a coupled process of uncoating/reverse transcription. (C) 1997 Federation of European B iochemical Societies.