title: Directed evolution of retrovirus envelope protein cytoplasmic tails guided by functional incorporation into lentivirus particles.
abstract: In contrast to most gammaretrovirus envelope proteins (Env), the Gibbon ape leukemia virus (GaLV) Env protein does not mediate the infectivity of human immunodeficiency virus type 1 (HIV-1) particles. We made use of this observation to set up a directed evolution system by creating a library of GaLV Env variants diversified at three critical amino acids, all located around the R-peptide cleavage site within the cytoplasmic tail. This library was screened for variants that were able to functionally pseudotype HIV-1 vector particles. All selected Env variants mediated the infectivity of HIV-1 vector particles and encoded novel cytoplasmic tail motifs. They were efficiently incorporated into HIV particles, and the R peptide was processed by the HIV protease. Interestingly, in some of the selected variants, the R-peptide cleavage site had shifted closer to the C terminus. These data demonstrate a valuable approach for the engineering of chimeric viruses and vector particles.
authors.affiliation: Division of Medical Biotechnology, Paul-Ehrlich-Institut, Paul-Ehrlich-Str. 51-59, 63225 Langen, Germany.
authors.forename: Christoph A
authors.initials: CA
authors.lastname: Merten
authors.forename: Jörn
authors.initials: J
authors.lastname: Stitz
authors.forename: Gundula
authors.initials: G
authors.lastname: Braun
authors.forename: Eric M
authors.initials: EM
authors.lastname: Poeschla
authors.forename: Klaus
authors.initials: K
authors.lastname: Cichutek
authors.forename: Christian J
authors.initials: CJ
authors.lastname: Buchholz
mesh_terms: D000595:Amino Acid Sequence; D002460:Cell Line; D019143:Evolution, Molecular; D015686:Gene Products, env / Q000235:genetics* / Q000378:metabolism; D005822:Genetic Vectors; D015497:HIV-1 / Q000235:genetics*; D006801:Humans; D017989:Leukemia Virus, Gibbon Ape / Q000737:chemistry*; D008969:Molecular Sequence Data; D010957:Plasmids; D014771:Virion / Q000235:genetics*
chemical_list: D015686:Gene Products, env