title: Changes in the accessibility of the HIV-1 Integrase C-terminus in the presence of cellular proteins.
abstract: BACKGROUND
  Following entry, uncoating, and reverse transcription, a number of cellular proteins become associated with the human immunodeficiency virus type 1 (HIV-1) pre-integration complex (PIC). With the goal of obtaining reagents for the analysis of the HIV-1 PIC composition and localisation, we have constructed functional integrase (IN) and matrix (MA) proteins that can be biotinylated during virus production and captured using streptavidin-coated beads.
  
  
  RESULTS
  Although the labelled C-terminus allows for the sensitive detection of virion-associated IN, it becomes inaccessible in the presence of cellular proteins. This masking is not dependent on the nature of the tag and does not occur with the tagged MA. It was not observed either with an IN mutant unable to interact with LEDGF/p75, or when LEDGF/p75 was depleted from cells.
  
  
  CONCLUSIONS
  Our observation suggests that a structural rearrangement or oligomerization of the IN protein occurs during the early steps of infection and that this process is related to the presence of LEDGF/p75.
authors.affiliation: Généthon, 1 rue de l'Internationale, Evry, 91002, France. olivier.danos@inserm.fr.
authors.forename: Sofia
authors.initials: S
authors.lastname: Benkhelifa-Ziyyat
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Bucher
authors.forename: Maria-Antonietta
authors.initials: MA
authors.lastname: Zanta-Boussif
authors.forename: Julie
authors.initials: J
authors.lastname: Pasquet
authors.forename: Olivier
authors.initials: O
authors.lastname: Danos
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D001710:Biotin / Q000378:metabolism; D002460:Cell Line; D019427:HIV Integrase / Q000737:chemistry / Q000378:metabolism*; D015497:HIV-1 / Q000502:physiology*; D006801:Humans; D008954:Models, Biological; D011485:Protein Binding; D011487:Protein Conformation; D055503:Protein Multimerization; D013194:Staining and Labeling / Q000379:methods; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C504649:PSIP1 protein, human; D014157:Transcription Factors; D001710:Biotin; D019427:HIV Integrase; C514801:p31 integrase protein, Human immunodeficiency virus 1