title: Dissociation of ligand-induced internalization of CXCR-4 from its co-receptor activity for HIV-1 Env-mediated membrane fusion.
abstract: The C-terminal cytoplasmic tail of chemokine receptors is important for their internalization upon ligand binding. We generated several deletion mutants of the C-terminal cytoplasmic tail of CXCR-4, a co-receptor for T cell line tropic strains of human immunodeficiency virus type 1 (HIV-1), to know whether or not co-receptor internalization is associated with HIV-1 entry. Our data showed that the removal of C-terminal 15 amino acid residues of the cytoplasmic tail from CXCR-4 completely abolished its internalization, but did not affect the co-receptor activity at all. Co-receptor activity was fully retained even when all 45 amino acid residues in the C-terminal cytoplasmic tail had been deleted. These data indicated that no cytoplasmic tail nor internalization of CXCR-4 is required for its co-receptor activity for HIV-1 entry.
authors.affiliation: Department of Viral Infection, Institute of Medical Science, University of Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Hu
authors.forename: T
authors.initials: T
authors.lastname: Shioda
authors.forename: T
authors.initials: T
authors.lastname: Hori
authors.forename: C
authors.initials: C
authors.lastname: Moriya
authors.forename: A
authors.initials: A
authors.lastname: Kato
authors.forename: Y
authors.initials: Y
authors.lastname: Sakai
authors.forename: K
authors.initials: K
authors.lastname: Matsushima
authors.forename: T
authors.initials: T
authors.lastname: Uchiyama
authors.forename: Y
authors.initials: Y
authors.lastname: Nagai
mesh_terms: D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D054377:Chemokine CXCL12; D019743:Chemokines, CXC / Q000494:pharmacology; D017931:DNA Primers / Q000235:genetics; D015536:Down-Regulation / Q000187:drug effects; D015686:Gene Products, env / Q000502:physiology*; D015497:HIV-1 / Q000472:pathogenicity* / Q000502:physiology; D006801:Humans; D008024:Ligands; D008561:Membrane Fusion / Q000502:physiology*; D051379:Mice; D016133:Polymerase Chain Reaction; D019718:Receptors, CXCR4 / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000494:pharmacology; D017384:Sequence Deletion
chemical_list: C515255:CXCL12 protein, human; D054377:Chemokine CXCL12; D019743:Chemokines, CXC; C515256:Cxcl12 protein, mouse; D017931:DNA Primers; D015686:Gene Products, env; D008024:Ligands; D019718:Receptors, CXCR4; D011994:Recombinant Proteins