Two nuclear localization signals in the HIV-1 matrix protein regulate nuclear import of the HIV-1 pre-integration complex

J Mol Biol. 2000 Jun 2;299(2):359-68. doi: 10.1006/jmbi.2000.3768.

Abstract

Replication of HIV-1 in non-dividing and slowly proliferating cell populations depends on active import of the viral pre-integration complex (PIC) into the cell nucleus. While it is commonly accepted that this process is mediated by an interaction between the HIV-1 PIC and the cellular nuclear import machinery, controversial results have been reported concerning the mechanisms of this interaction. Here, we demonstrate that a recently identified nuclear localization signal within the HIV-1 matrix protein (MA), MA NLS-2, together with previously described MA NLS-1, mediates nuclear import of the HIV-1 PIC. Inactivation of both MA NLSs precluded nuclear translocation of MA and rendered the virus defective in nuclear import and replication in non-dividing macrophage cultures, even when functional Vpr and integrase (IN), two more viral proteins implicated in HIV-1 nuclear import, were present. Taken together, these results indicate that Vpr does not function as an independent nuclear import factor and demonstrate that HIV-1 MA, by virtue of its two nuclear localization signals, regulates HIV-1 nuclear import.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Biological Transport
  • Cell Division
  • Cell Nucleus / metabolism*
  • Cells, Cultured
  • DNA, Viral / analysis
  • DNA, Viral / genetics
  • Gene Products, gag / chemistry*
  • Gene Products, gag / genetics
  • Gene Products, gag / metabolism*
  • Gene Products, vpr / genetics
  • Gene Products, vpr / metabolism
  • HIV Antigens / chemistry*
  • HIV Antigens / genetics
  • HIV Antigens / metabolism*
  • HIV Integrase / genetics
  • HIV Integrase / metabolism
  • HIV Reverse Transcriptase / metabolism
  • HIV-1 / enzymology
  • HIV-1 / genetics
  • HIV-1 / metabolism
  • HIV-1 / physiology*
  • Humans
  • Macrophages / cytology
  • Macrophages / virology
  • Mutation / genetics
  • Nuclear Localization Signals / genetics
  • Nuclear Localization Signals / physiology*
  • Nuclear Proteins / metabolism
  • Precipitin Tests
  • Protein Binding
  • Viral Proteins*
  • Virus Integration*
  • Virus Replication
  • alpha Karyopherins
  • gag Gene Products, Human Immunodeficiency Virus
  • vpr Gene Products, Human Immunodeficiency Virus

Substances

  • DNA, Viral
  • Gene Products, gag
  • Gene Products, vpr
  • HIV Antigens
  • Nuclear Localization Signals
  • Nuclear Proteins
  • Viral Proteins
  • alpha Karyopherins
  • gag Gene Products, Human Immunodeficiency Virus
  • p17 protein, Human Immunodeficiency Virus Type 1
  • vpr Gene Products, Human Immunodeficiency Virus
  • HIV Integrase
  • HIV Reverse Transcriptase