Modulation of the antigen transport machinery TAP by friends and enemies

FEBS Lett. 2006 Feb 13;580(4):1156-63. doi: 10.1016/j.febslet.2005.11.048. Epub 2005 Dec 6.

Abstract

The transporter associated with antigen processing (TAP) is a key factor of the major histocompatibility complex (MHC) class I antigen presentation pathway. This ABC transporter translocates peptides derived mainly from proteasomal degradation from the cytosol into the ER lumen for loading onto MHC class I molecules. Manifold mechanisms have evolved to regulate TAP activity. During infection, TAP expression is upregulated by interferon-gamma. Furthermore, the assembly and stability of the transport complex is promoted by various auxiliary factors. However, tumors and viruses have developed sophisticated strategies to escape the immune surveillance by suppressing TAP function. The activity of TAP can be impaired on the transcriptional or translational level, by enhanced degradation or by inhibition of peptide translocation. In this review, we briefly summarize existing data concerning the regulation of the TAP complex.

Publication types

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

MeSH terms

  • ATP-Binding Cassette Transporters
  • Histocompatibility Antigens Class I / immunology
  • Histocompatibility Antigens Class I / physiology*
  • Humans
  • Major Histocompatibility Complex / physiology
  • Viruses / immunology

Substances

  • ATP-Binding Cassette Transporters
  • Histocompatibility Antigens Class I
  • transporter associated with antigen processing (TAP)