De novo synthesis, uptake and proteolytic processing of lipocalin-type prostaglandin D synthase, beta-trace, in the kidneys

FEBS J. 2009 Dec;276(23):7146-58. doi: 10.1111/j.1742-4658.2009.07426.x. Epub 2009 Oct 29.


Lipocalin-type prostaglandin D synthase (L-PGDS) is a multifunctional protein that produces prostaglandin D(2) and binds and transports various lipophilic substances after secretion into various body fluids as beta-trace. L-PGDS has been proposed to be a useful diagnostic marker for renal injury associated with diabetes or hypertension, because the urinary and plasma concentrations are increased in patients with these diseases. However, it remains unclear whether urinary L-PGDS is synthesized de novo in the kidney or taken up from the blood circulation. In crude extracts of monkey kidney and human urine, we found L-PGDS with its original N-terminal sequence starting from Ala23 after the signal sequence, and also its N-terminal-truncated products starting from Gln31 and Phe34. In situ hybridization and immunohistochemical staining with monoclonal antibody 5C11, which recognized the amino-terminal Ala23-Val28 loop of L-PGDS, revealed that both the mRNA and the intact form of L-PGDS were localized in the cells of Henle's loop and the glomeruli of the kidney, indicating that L-PGDS is synthesized de novo in these tissues. However, truncated forms of L-PGDS were found in the lysosomes of tubular cells, as visualized by immunostaining with 10A5, another monoclonal antibody, which recognized the three-turn alpha-helix between Arg156 and Thr173. These results suggest that L-PGDS is taken up by tubular cells and actively degraded within their lysosomes to produce the N-terminal-truncated form.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antibodies, Monoclonal / immunology
  • Haplorhini
  • Humans
  • In Situ Hybridization
  • Intramolecular Oxidoreductases / biosynthesis*
  • Intramolecular Oxidoreductases / genetics
  • Kidney / enzymology*
  • Kidney / metabolism
  • Lipocalins / biosynthesis*
  • Lipocalins / genetics
  • Models, Molecular
  • Molecular Sequence Data
  • Protein Conformation
  • Rats
  • Rats, Sprague-Dawley
  • Sequence Alignment


  • Antibodies, Monoclonal
  • Lipocalins
  • Intramolecular Oxidoreductases
  • prostaglandin R2 D-isomerase