title: Association of human immunodeficiency virus Nef protein with actin is myristoylation dependent and influences its subcellular localization.
abstract: Human immunodeficiency virus (HIV) Nef functions are thought to be mediated via interactions with cellular proteins. Utilizing zone velocity sedimentation in glycerol gradients we found that recombinant HIV-1 Nef non-covalently associates with actin forming a high-molecular-mass complex of 150-300 kDa. This Nef/actin complex was present in human B and T lymphocytes but not in insect cells and was dependent on the N-terminal myristoylation of Nef, whereas the SH3-binding proline motif of Nef was not involved. Despite being myristoylated, HIV-2 Nef did not associate with actin. This might reflect differences in the subcellular localization of Nef since cell-fractionation experiments revealed that HIV-1 Nef was virtually exclusively localized in the cytoskeletal (detergent-insoluble) fraction whereas HIV-2 Nef had significantly reduced affinity for the cytoskeleton. Colocalization experiments in HIV-1-infected CD4+ fibroblasts revealed that Nef/actin complexes may also exist in HIV-infected cells. This novel interaction of HIV-1 Nef with actin provides insight into the association of Nef with cellular structures and reveals general differences in the interactions of the Nef proteins from HIV-1 and HIV-2.
authors.affiliation: Universitätskliniken des Saarlandes, Institut für Med. Mikrobiologie und Hygiene, Abt. Virologie, Homburg/Saar, Germany.
authors.forename: O T
authors.initials: OT
authors.lastname: Fackler
authors.forename: N
authors.initials: N
authors.lastname: Kienzle
authors.forename: E
authors.initials: E
authors.lastname: Kremmer
authors.forename: A
authors.initials: A
authors.lastname: Boese
authors.forename: B
authors.initials: B
authors.lastname: Schramm
authors.forename: T
authors.initials: T
authors.lastname: Klimkait
authors.forename: C
authors.initials: C
authors.lastname: Kücherer
authors.forename: N
authors.initials: N
authors.lastname: Mueller-Lantzsch
mesh_terms: D000199:Actins / Q000378:metabolism*; D000818:Animals; D002460:Cell Line; D015693:Gene Products, nef / Q000737:chemistry / Q000378:metabolism*; D015497:HIV-1 / Q000378:metabolism*; D015498:HIV-2 / Q000378:metabolism*; D008970:Molecular Weight; D019814:Myristic Acid; D009227:Myristic Acids / Q000378:metabolism; D011485:Protein Binding; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D018411:Spodoptera; D013347:Subcellular Fractions / Q000378:metabolism*; D013601:T-Lymphocytes / Q000378:metabolism; D054311:nef Gene Products, Human Immunodeficiency Virus
chemical_list: D000199:Actins; D015693:Gene Products, nef; D009227:Myristic Acids; D011994:Recombinant Proteins; D054311:nef Gene Products, Human Immunodeficiency Virus; D019814:Myristic Acid