The beta7 integrin gene (Itgb-7) promoter is responsive to TGF-beta1: defining control regions

Immunogenetics. 1998 Aug;48(3):184-95. doi: 10.1007/s002510050422.

Abstract

The beta7 integrins LPAM-1 (alpha4beta7) and M290 (alphaEbeta7) mediate the homing of lymphocytes to gut-associated lymphoid tissue, and the proposed retention of intraepithelial lymphocytes (IEL), respectively. Here we show that the gut mucosal cytokine TGF- beta1 increases the expression of beta7 and alphaE subunit mRNA transcripts and the cell-surface expression of M290 on T cells, and that it decreases the level of alpha4 integrin transcripts. Induced beta7 integrin gene expression was inhibited by the protein tyrosine kinase inhibitor genistein, implicating a role for tyrosine phosphorylation. An analysis of the beta7 integrin gene promoter revealed three DNAse I hypersensitivity sites, two of which mapped to the 5' and 3' ends of a promoter fragment (nucleotides +690 to +63) that directed both the basal and the TGF-beta1-induced expression of a heterologous reporter gene. Deletion analysis identified two TGF-beta1 response regions encompassing nucleotides -509 to -398 (TGFBRR1), and -122 to +32 (TGFBRR2). TGFBRR1 interacted with at least five protein complexes, whose binding could be induced with TGF-beta1 stimulation and could be antagonized by TGFBRR2 which harbored both similar and distinctive cis-elements. TGFBRR2 interacted specifically with at least two major nuclear protein complexes, whose binding was phosphorylation dependent. These data provide new insights into the mechanism by which TGF-beta may switch LPAM-1(+ve) migrating T cells to express M290, facilitating their retention in the gut.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Binding Sites / genetics
  • Cell Line
  • DNA / genetics
  • Deoxyribonuclease I
  • Integrin beta Chains*
  • Integrins / chemistry
  • Integrins / genetics*
  • Intestinal Mucosa / cytology
  • Intestinal Mucosa / immunology
  • Mice
  • Molecular Sequence Data
  • Nuclear Proteins / metabolism
  • Oligonucleotide Probes / genetics
  • Phosphorylation
  • Promoter Regions, Genetic / drug effects*
  • Protein Conformation
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • T-Lymphocytes / cytology
  • T-Lymphocytes / immunology
  • Transforming Growth Factor beta / pharmacology*
  • Tyrosine / genetics
  • Tyrosine / metabolism

Substances

  • Integrin beta Chains
  • Integrins
  • Nuclear Proteins
  • Oligonucleotide Probes
  • RNA, Messenger
  • Transforming Growth Factor beta
  • integrin alpha4beta7
  • integrin alphaEbeta7
  • integrin beta7
  • Tyrosine
  • DNA
  • Deoxyribonuclease I

Associated data

  • GENBANK/U97031