title: Dynamin 2 is required for the enhancement of HIV-1 infectivity by Nef.
abstract: Nef is a virulence factor of HIV-1 and other primate lentiviruses that is crucial for rapid progression to AIDS. In cell culture, Nef increases the infectivity of HIV-1 progeny virions by an unknown mechanism. We now show that dynamin 2 (Dyn2), a key regulator of vesicular trafficking, is a binding partner of Nef that is required for its ability to increase viral infectivity. Dominant-negative Dyn2 or the depletion of Dyn2 by small interfering RNA potently inhibited the effect of Nef on HIV-1 infectivity. Furthermore, in Dyn2-depleted cells, this function of Nef could be rescued by ectopically expressed Dyn2 but not by Dyn1, a closely related isoform that does not bind Nef. The infectivity enhancement by Nef also depended on clathrin, because it was diminished in clathrin-depleted cells and profoundly inhibited in cells expressing the clathrin-binding domain of AP180, which blocks clathrin-coated pit formation but not clathrin-independent endocytosis. Together, these findings imply that the infectivity enhancement activity of Nef depends on Dyn2- and clathrin-mediated membrane invagination events.
authors.affiliation: Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, MA 02115, USA. m.pizzato@imperial.ac.uk
authors.forename: Massimo
authors.initials: M
authors.lastname: Pizzato
authors.forename: Anna
authors.initials: A
authors.lastname: Helander
authors.forename: Elena
authors.initials: E
authors.lastname: Popova
authors.forename: Arianna
authors.initials: A
authors.lastname: Calistri
authors.forename: Alessia
authors.initials: A
authors.lastname: Zamborlini
authors.forename: Giorgio
authors.initials: G
authors.lastname: Palù
authors.forename: Heinrich G
authors.initials: HG
authors.lastname: Göttlinger
mesh_terms: D000818:Animals; D019556:COS Cells; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism / Q000821:virology; D002522:Chlorocebus aethiops; D034285:Dynamin II / Q000502:physiology*; D015693:Gene Products, nef / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D015658:HIV Infections / Q000378:metabolism; D015497:HIV-1 / Q000472:pathogenicity* / Q000502:physiology; D006801:Humans; D019169:Jurkat Cells; D011485:Protein Binding / Q000502:physiology; D014771:Virion / Q000472:pathogenicity / Q000502:physiology; D054311:nef Gene Products, Human Immunodeficiency Virus
chemical_list: D015693:Gene Products, nef; D054311:nef Gene Products, Human Immunodeficiency Virus; C514837:nef protein, Human immunodeficiency virus 1; D034285:Dynamin II