title: Influence of extended mutations of the HIV-1 transframe protein p6 on Nef-dependent viral replication and infectivity in vitro.
abstract: The HIV-1 transframe protein p6 known to modulate HIV-1 protease activation has been suggested to interact with the viral pathogenicity factor Nef. However, a potential interaction site in p6 has not been mapped so far. To evaluate effects of p6 modification on viral replication in light of Nef function, clustered substitutions were introduced into the central p6 region of the infectious provirus NL4-3 and virus growth and composition of the various mutants was analyzed in different cell cultures in the presence or absence of Nef. Whereas clustered p6 substitutions did neither affect particle incorporation of Nef, nor precursor maturation or viral infectivity, a simultaneous substitution of 40 of the total 56 p6 residues significantly diminished viral infectivity and replication in a Nef-independent manner. Furthermore, this extended modification was not capable of rescuing the negative effects of a transdominant Nef mutant on particle production suggesting that the proposed target for Nef interaction in Gag-Pol is located outside the modified p6 region. In sum these data strongly argue against a functional connection of the central p6 region and Nef during viral life cycle.
authors.affiliation: Molecular Microbiology and Gene Therapy, Institute of Medical Microbiology and Hygiene, University of Regensburg, Franz-Josef-Straubeta Allee 11, D-93053 Regensburg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Leiherer
authors.forename: Christine
authors.initials: C
authors.lastname: Ludwig
authors.forename: Ralf
authors.initials: R
authors.lastname: Wagner
mesh_terms: D002460:Cell Line; D004847:Epithelial Cells / Q000821:virology; D015497:HIV-1 / Q000235:genetics* / Q000472:pathogenicity*; D006367:HeLa Cells; D006801:Humans; D009154:Mutation / Q000235:genetics*; D014771:Virion / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology; D014779:Virus Replication / Q000235:genetics*; D054301:gag Gene Products, Human Immunodeficiency Virus / Q000235:genetics* / Q000378:metabolism*; D054311:nef Gene Products, Human Immunodeficiency Virus / Q000378:metabolism*
chemical_list: D054301:gag Gene Products, Human Immunodeficiency Virus; D054311:nef Gene Products, Human Immunodeficiency Virus; C083002:p6 gag protein, Human immunodeficiency virus 1