Cis elements for transporter associated with antigen-processing-2 transcription: two new promoters and an essential role of the IFN response factor binding element in IFN-gamma-mediated activation of the transcription initiator

Int Immunol. 2002 Feb;14(2):189-200. doi: 10.1093/intimm/14.2.189.

Abstract

Expression of cell surface MHC class I:peptide complex requires coordinated expression of multiple genes such as MHC class I heavy chain, beta(2)-microglobulin (beta(2)m), transporters associated with antigen-processing (TAP)-1 and TAP-2, and proteosomal components low-molecular weight polypeptide (LMP)-2 and LMP-7. All of these genes are expressed at defined and distinct levels in normal tissues, and are inducible by IFN-gamma. While the cis elements involved in transcription of the MHC class I heavy chain, beta(2)m, TAP-1 and LMP-2 have been analyzed extensively, those for TAP-2 and LMP-7 have not been well studied. Here we systematically analyzed the cis elements for TAP-2 transcription. We found at least two independent elements that are sufficient to activate transcription of a reporter gene. One (hereby called TAP-2 P1) is located 5' to the TAP-2 exon 1, while the other (hereby called TAP-2 P2) is a transcription initiator residing in intron 1. Analysis of the 5' sequence of TAP-2 mRNA indicates that both promoters are active. Moreover, while the TAP-2 promoter region contains cis elements that can mediate TAP-2 induction by IFN-gamma, such as gamma-activation site and IFN response factor binding element (IRFE), only the IRFE is required for IFN-gamma induction of TAP-2 promoter in vitro. The IRFE appears to work as an enhancer for the initiator (P2). Together with another promoter recently identified by others, TAP-2 therefore has three independent promoters that can be differentially regulated.

Publication types

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

MeSH terms

  • ATP-Binding Cassette Transporters / genetics*
  • Amino Acid Transport Systems*
  • Base Sequence
  • Enhancer Elements, Genetic
  • Exoribonucleases
  • Interferon-gamma / pharmacology*
  • Molecular Sequence Data
  • Promoter Regions, Genetic / physiology*
  • Response Elements*
  • Saccharomyces cerevisiae Proteins
  • Transcription, Genetic*

Substances

  • ATP-Binding Cassette Transporters
  • Amino Acid Transport Systems
  • Saccharomyces cerevisiae Proteins
  • TAT2 protein, S cerevisiae
  • Interferon-gamma
  • Exoribonucleases