title: An amphipathic sequence in the cytoplasmic tail of HIV-1 Env alters cell tropism and modulates viral receptor specificity.
abstract: The human immunodeficiency virus type 1 (HIV-1) 92UG046 Env protein, obtained from a CD4-independent HIV-1 primary isolate (Zerhouni et al., 2004), has the ability to initiate an infection in HeLa cells expressing CD4 when carrying the full-length (FL) Env, but uses CD8 molecules for receptor-mediated entry when carrying a truncated Env (CT84). To determine whether a specific length or structure in the cytoplasmic tail (CT) is responsible for this alteration of tropism, we compared a series of Env constructs with different CT truncations and the presence or absence of an amphipathic alpha- helical sequence. We found that truncated constructs containing the alpha-helical LLP-2 structure in their CT domains conferred a switch from CD4 to CD8 tropism. The results support the conclusion that the structure of the CT domain can play an important role in determining receptor specificity.
authors.forename: A N
authors.initials: AN
authors.lastname: Vzorov
authors.forename: C
authors.initials: C
authors.lastname: Yang
authors.forename: R W
authors.initials: RW
authors.lastname: Compans
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002478:Cells, Cultured; D003593:Cytoplasm / Q000737:chemistry*; D015497:HIV-1 / Q000502:physiology*; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D015728:Receptors, HIV / Q000502:physiology*; D018523:Tropism; D054299:env Gene Products, Human Immunodeficiency Virus / Q000737:chemistry* / Q000502:physiology
chemical_list: D015728:Receptors, HIV; D054299:env Gene Products, Human Immunodeficiency Virus
keywords: CD8; receptor specificity.; HIV-1; Env glycoprotein; gp41; gp120; cytoplasmic tail truncation; alpha-helical LLP2 sequence; CD4