title: Human immunodeficiency virus type 1 envelope proteins traffic toward virion assembly sites via a TBC1D20/Rab1-regulated pathway.
abstract: BACKGROUND
  The cellular activity of many factors and pathways is required to execute the complex replication cycle of the human immunodeficiency virus type 1 (HIV-1). To reveal these cellular components, several extensive RNAi screens have been performed, listing numerous 'HIV-dependency factors'. However, only a small overlap between these lists exists, calling for further evaluation of the relevance of specific factors to HIV-1 replication and for the identification of additional cellular candidates. TBC1D20, the GTPase-activating protein (GAP) of Rab1, regulates endoplasmic reticulum (ER) to Golgi trafficking, was not identified in any of these screens, and its involvement in HIV-1 replication cycle is tested here.
  
  
  RESULTS
  Excessive TBC1D20 activity perturbs the early trafficking of HIV-1 envelope protein through the secretory pathway. Overexpression of TBC1D20 hampered envelope processing and reduced its association with detergent-resistant membranes, entailing a reduction in infectivity of HIV-1 virion like particles (VLPs).
  
  
  CONCLUSIONS
  These findings add TBC1D20 to the network of host factors regulating HIV replication cycle.
authors.affiliation: Department of Cell Research and Immunology, The George S, Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
authors.forename: Dikla
authors.initials: D
authors.lastname: Nachmias
authors.forename: Ella H
authors.initials: EH
authors.lastname: Sklan
authors.forename: Marcelo
authors.initials: M
authors.lastname: Ehrlich
authors.forename: Eran
authors.initials: E
authors.lastname: Bacharach
mesh_terms: D002460:Cell Line; D015497:HIV-1 / Q000472:pathogenicity*; D054884:Host-Pathogen Interactions; D006801:Humans; D021381:Protein Transport; D014779:Virus Replication; D054299:env Gene Products, Human Immunodeficiency Virus / Q000378:metabolism*; D020761:rab1 GTP-Binding Proteins / Q000378:metabolism*
chemical_list: C526344:TBC1D20 protein, human; D054299:env Gene Products, Human Immunodeficiency Virus; D020761:rab1 GTP-Binding Proteins