Amino-terminal substitutions in the CCR5 coreceptor impair gp120 binding and human immunodeficiency virus type 1 entry

J Virol. 1998 Jan;72(1):279-85. doi: 10.1128/JVI.72.1.279-285.1998.

Abstract

The CC-chemokine receptor CCR5 is required for the efficient fusion of macrophage (M)-tropic human immunodeficiency virus type 1 (HIV-1) strains with the plasma membrane of CD4+ cells and interacts directly with the viral surface glycoprotein gp120. Although receptor chimera studies have provided useful information, the domains of CCR5 that function for HIV-1 entry, including the site of gp120 interaction, have not been unambiguously identified. Here, we use site-directed, alanine-scanning mutagenesis of CCR5 to show that substitutions of the negatively charged aspartic acid residues at positions 2 and 11 (D2A and D11A) and a glutamic acid residue at position 18 (E18A), individually or in combination, impair or abolish CCR5-mediated HIV-1 entry for the ADA and JR-FL M-tropic strains and the DH123 dual-tropic strain. These mutations also impair Env-mediated membrane fusion and the gp120-CCR5 interaction. Of these three residues, only D11 is necessary for CC-chemokine-mediated inhibition of HIV-1 entry, which is, however, also dependent on other extracellular CCR5 residues. Thus, the gp120 and CC-chemokine binding sites on CCR5 are only partially overlapping, and the former site requires negatively charged residues in the amino-terminal CCR5 domain.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Amino Acids / chemistry
  • Binding Sites / genetics
  • CCR5 Receptor Antagonists
  • CD4-Positive T-Lymphocytes / physiology
  • CD4-Positive T-Lymphocytes / virology
  • Cell Fusion
  • Cell Line
  • Chemokines / pharmacology
  • Electrochemistry
  • HIV Envelope Protein gp120 / metabolism*
  • HIV-1 / pathogenicity*
  • HIV-1 / physiology*
  • Humans
  • Macrophages / physiology
  • Macrophages / virology
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed
  • Protein Binding
  • Receptors, CCR5 / genetics*
  • Receptors, CCR5 / physiology*

Substances

  • Amino Acids
  • CCR5 Receptor Antagonists
  • Chemokines
  • HIV Envelope Protein gp120
  • Receptors, CCR5