A noncanonical mu-1A-binding motif in the N terminus of HIV-1 Nef determines its ability to downregulate major histocompatibility complex class I in T lymphocytes

J Virol. 2012 Apr;86(7):3944-51. doi: 10.1128/JVI.06257-11. Epub 2012 Feb 1.

Abstract

Downregulation of major histocompatibility complex class I (MHC-I) by HIV-1 Nef protein is indispensable for evasion of protective immunity by HIV-1. Though it has been suggested that the N-terminal region of Nef contributes to the function by associating with a mu-1A subunit of adaptor protein 1, the structural basis of the interaction between Nef and mu-1A remains elusive. We found that a tripartite hydrophobic motif (Trp13/Val16/Met20) in the N terminus of Nef was required for the MHC-I downregulation. Importantly, the motif functioned as a noncanonical mu-1A-binding motif for the interaction with the tyrosine motif-binding site of the mu-1A subunit. Our findings will help understanding of how HIV-1 evades the antiviral immune response by selectively redirecting the cellular protein trafficking system.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Protein Complex 1 / genetics
  • Adaptor Protein Complex 1 / metabolism*
  • Adaptor Protein Complex mu Subunits / genetics
  • Adaptor Protein Complex mu Subunits / metabolism*
  • Amino Acid Motifs
  • Amino Acid Sequence
  • Binding Sites
  • Down-Regulation*
  • HIV Infections / genetics
  • HIV Infections / metabolism*
  • HIV Infections / virology
  • HIV-1 / chemistry
  • HIV-1 / genetics
  • HIV-1 / metabolism*
  • Histocompatibility Antigens Class I / genetics*
  • Histocompatibility Antigens Class I / metabolism
  • Humans
  • Molecular Sequence Data
  • Protein Binding
  • T-Lymphocytes / metabolism*
  • T-Lymphocytes / virology
  • nef Gene Products, Human Immunodeficiency Virus / chemistry*
  • nef Gene Products, Human Immunodeficiency Virus / genetics
  • nef Gene Products, Human Immunodeficiency Virus / metabolism*

Substances

  • AP1M1 protein, human
  • Adaptor Protein Complex 1
  • Adaptor Protein Complex mu Subunits
  • Histocompatibility Antigens Class I
  • nef Gene Products, Human Immunodeficiency Virus
  • nef protein, Human immunodeficiency virus 1