Gene structure and properties of TIGR, an olfactomedin-related glycoprotein cloned from glucocorticoid-induced trabecular meshwork cells

J Biol Chem. 1998 Mar 13;273(11):6341-50. doi: 10.1074/jbc.273.11.6341.

Abstract

Expression of the trabecular meshwork inducible glucocorticoid response (TIGR) gene progressively increases from barely detectable levels to greater than 2% of total cellular mRNA over 10 days exposure of trabecular meshwork (TM) cells to dexamethasone. Cycloheximide blocked most of the TIGR mRNA induction, suggesting a requirement for ongoing protein synthesis. The genomic structure of TIGR (approximately 20 kilobases) consists of 3 exons, and a 5-kilobase promoter region that contains 13 predicted hormone response elements, including several glucocorticoid regulatory elements, and other potentially important regulatory motifs. TIGR cDNA encodes an olfactomedin-related glycoprotein of 504 amino acids with motifs for N- and O-linked glycosylation, glycosaminoglycan initiation, hyaluronic acid binding, and leucine zippers. Recombinant TIGR (rTIGR) showed oligomerization and specific binding to TM cells. Anti-rTIGR antibody detected multiple translational/post-translational forms of TIGR produced by the cells (including secreted 66 kDa/55 kDa glycoproteins/proteins in the media and 55 kDa cellular proteins), whereas Northern blot showed a single mRNA species. The findings suggest potential mechanisms by which TIGR could obstruct the aqueous humor fluid flow and participate in the pathogenesis of glaucoma.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Cloning, Molecular
  • Cytoskeletal Proteins
  • Dexamethasone / pharmacology
  • Dimerization
  • Extracellular Matrix Proteins / genetics
  • Eye Proteins / genetics*
  • Glaucoma / etiology
  • Glucocorticoids / pharmacology
  • Glycoproteins / genetics*
  • Humans
  • Leucine Zippers*
  • Molecular Sequence Data
  • Organ Culture Techniques
  • Protein Processing, Post-Translational
  • Sequence Homology, Amino Acid
  • Trabecular Meshwork / drug effects
  • Trabecular Meshwork / physiology*

Substances

  • Cytoskeletal Proteins
  • Extracellular Matrix Proteins
  • Eye Proteins
  • Glucocorticoids
  • Glycoproteins
  • olfactomedin
  • trabecular meshwork-induced glucocorticoid response protein
  • Dexamethasone

Associated data

  • GENBANK/AF007562
  • GENBANK/AF007563
  • GENBANK/AF007564
  • GENBANK/AF007565
  • GENBANK/AF007566
  • GENBANK/AF012654
  • GENBANK/U85257