title: Binding of HIV-1 Nef to a novel thioesterase enzyme correlates with Nef-mediated CD4 down-regulation.
abstract: Nef is a 27-kDa myristoylated protein conserved in primate lentiviruses. In vivo, simian immunodeficiency virus Nef is required in macaques to produce a high viral load and full pathological effects. Nef has at least three major effects in vitro, induction of CD4 down-regulation, alteration of T cell activation pathways, and enhancement of viral infectivity. We have used the yeast two-hybrid system to identify cellular proteins that interact with HIV-1Lai Nef and could mediate Nef function. A human cDNA was isolated that encodes a new type of thioesterase, an enzyme that cleaves thioester bonds. This novel thioesterase is unlike the animal types I and II thioesterases previously cloned but is homologous to the Escherichia coli thioesterase II. Nef and this thioesterase interact in vitro and are co-immunoprecipitated by anti-Nef antibodies in CEM cells expressing Nef. Nef alleles from human immunodeficiency virus-1 (HIV-1) isolates unable to down-regulate CD4 do not react or react poorly with thioesterase. An HIV-1 NefLai mutant selected for its lack of interaction with thioesterase was also unable to down-regulate CD4 cell-surface expression. These observations suggest that this human thioesterase is a cellular mediator of Nef-induced CD4 down-regulation.
authors.affiliation: Institut Cochin de Génétique Moléculaire, INSERM U332, Université Paris V, 24 Rue du Faubourg Saint-Jacques, 75014 Paris, France.
authors.forename: L X
authors.initials: LX
authors.lastname: Liu
authors.forename: F
authors.initials: F
authors.lastname: Margottin
authors.forename: S
authors.initials: S
authors.lastname: Le Gall
authors.forename: O
authors.initials: O
authors.lastname: Schwartz
authors.forename: L
authors.initials: L
authors.lastname: Selig
authors.forename: R
authors.initials: R
authors.lastname: Benarous
authors.forename: S
authors.initials: S
authors.lastname: Benichou
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D015704:CD4 Antigens / Q000378:metabolism*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry; D015536:Down-Regulation; D004926:Escherichia coli / Q000201:enzymology; D064429:Fatty Acid Synthases / Q000235:genetics / Q000378:metabolism; D015693:Gene Products, nef / Q000378:metabolism*; D015497:HIV-1; D006801:Humans; D066298:In Vitro Techniques; D019169:Jurkat Cells; D008969:Molecular Sequence Data; D010170:Palmitoyl-CoA Hydrolase; D011506:Proteins; D011994:Recombinant Proteins / Q000378:metabolism; D013601:T-Lymphocytes / Q000378:metabolism; D013869:Thiolester Hydrolases / Q000235:genetics / Q000378:metabolism*; D054311:nef Gene Products, Human Immunodeficiency Virus; D012359:tRNA Methyltransferases
chemical_list: D015704:CD4 Antigens; D018076:DNA, Complementary; D015693:Gene Products, nef; D011506:Proteins; D011994:Recombinant Proteins; D054311:nef Gene Products, Human Immunodeficiency Virus; C498548:TRMO protein, human; D012359:tRNA Methyltransferases; D064429:Fatty Acid Synthases; D013869:Thiolester Hydrolases; C022738:thioesterase II; C106353:ACOT8 protein, human; D010170:Palmitoyl-CoA Hydrolase