Proline-rich (PxxP) motifs in HIV-1 Nef bind to SH3 domains of a subset of Src kinases and are required for the enhanced growth of Nef+ viruses but not for down-regulation of CD4

EMBO J. 1995 Feb 1;14(3):484-91. doi: 10.1002/j.1460-2075.1995.tb07024.x.

Abstract

Human immunodeficiency virus (HIV) and simian immunodeficiency virus Nef proteins contain a conserved motif with the minimal consensus (PxxP) site for Src homology region 3 (SH3)-mediated protein-protein interactions. Nef PxxP motifs show specific binding to biotinylated SH3 domains of Hck and Lyn, but not to those of other tested Src family kinases or less related proteins. A unique cooperative role of a distant proline is also observed. Endogenous Hck of monocytic U937 cells can be specifically precipitated by matrix-bound HIV-1 Nef, but not by mutant protein lacking PxxP. Intact Nef PxxP motifs are dispensable for Nef-induced CD4 down-regulation, but are required for the higher in vitro replicative potential of Nef+ viruses. Thus, CD4 down-regulation and promotion of viral growth are two distinct functions of Nef, and the latter is mediated via SH3 binding.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • CD4 Antigens / genetics
  • Down-Regulation
  • Gene Products, nef / genetics
  • Gene Products, nef / metabolism*
  • Glutathione Transferase / biosynthesis
  • Glutathione Transferase / genetics
  • HIV-1 / genetics
  • HIV-1 / growth & development*
  • HIV-1 / immunology
  • Humans
  • Leukocytes, Mononuclear / immunology
  • Leukocytes, Mononuclear / virology
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed
  • Proline / metabolism
  • Protein Binding
  • Protein-Tyrosine Kinases / classification
  • Protein-Tyrosine Kinases / metabolism*
  • Proto-Oncogene Proteins / metabolism
  • Proto-Oncogene Proteins c-hck
  • Recombinant Fusion Proteins / metabolism
  • Structure-Activity Relationship
  • nef Gene Products, Human Immunodeficiency Virus
  • src-Family Kinases*

Substances

  • CD4 Antigens
  • Gene Products, nef
  • Proto-Oncogene Proteins
  • Recombinant Fusion Proteins
  • nef Gene Products, Human Immunodeficiency Virus
  • Proline
  • Glutathione Transferase
  • Protein-Tyrosine Kinases
  • HCK protein, human
  • Proto-Oncogene Proteins c-hck
  • lyn protein-tyrosine kinase
  • src-Family Kinases