title: A 100-amino acid truncation in the cytoplasmic tail of glycoprotein 41 in the reference HIV type 1 strain RF.
abstract: Truncations of the cytoplasmic tail of the HIV-1 transmembrane (TM) protein are rare and almost always markedly reduce virus infectivity. We describe a truncation of the gp41 cytoplasmic tail in the commonly used early HIV-1 reference strain RF. This truncation apparently arose after continuous passage in H9 cells. We detected the truncation by Western blot as a size decrease in RF gp41 from 46 to approximately 34 kDa. The reduced size of RF gp41 observed was not due to differences in glycosylation. Viral DNA sequencing confirmed that a point mutation at Env residue 740 (Trp) introduced a premature stop codon, resulting in a 100-amino acid (13-kDa) truncation of the gp41 C terminus. This truncated RF species, termed RF(gp34), was characterized phenotypically by growth in Hut78 cells. Compared with other B clade HIV strains (IIIB, SF2, and NL4.3), RF(gp34) induced massive syncytia. Importantly, RF(gp34) also productively infected peripheral blood mononuclear cells in vitro.
authors.affiliation: Centre for Immunology, St. Vincent's Hospital, Darlinghurst, Sydney, NSW 2010, Australia.
authors.forename: Darren R
authors.initials: DR
authors.lastname: Jones
authors.forename: Kazuo
authors.initials: K
authors.lastname: Suzuki
authors.forename: Sabine C
authors.initials: SC
authors.lastname: Piller
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D004279:DNA, Viral / Q000032:analysis; D017353:Gene Deletion; D015726:Giant Cells / Q000473:pathology / Q000821:virology; D015700:HIV Envelope Protein gp41 / Q000235:genetics*; D015658:HIV Infections / Q000821:virology*; D015497:HIV-1 / Q000145:classification / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009000:Monocytes / Q000821:virology; D017354:Point Mutation; D014364:Tryptophan / Q000235:genetics*; D014407:Tumor Cells, Cultured / Q000821:virology
chemical_list: D004279:DNA, Viral; D015700:HIV Envelope Protein gp41; D014364:Tryptophan