title: Does Tamm-Horsfall protein-uric acid binding play a significant role in urate homeostasis?
abstract: BACKGROUND
  Mutations in Tamm-Horsfall protein (THP), also known as uromodulin, lead to a group of diseases known as the uromodulin storage disorders. Clinically, these diseases present with tubulo-interstitial damage, progressive renal dysfunction, hyperuricaemia, and gout. However, it remains unclear how a mutation in THP, a protein produced in the thick ascending limb, can cause hyperuricaemia when most of the uric acid transport is believed to occur in the proximal tubule. However, one study in humans suggests that uric acid could also be secreted in the distal tubule. Thus, an attractive hypothesis could be that THP would bind to uric acid in the distal tubule, and decrease its subsequent reabsorption in the distal nephron.
  
  
  METHODS
  We screened for uric acid binding to THP using four independent binding assays.
  
  
  RESULTS
  There was no evidence that uric acid could bind to THP.
  
  
  CONCLUSIONS
  THP-uric acid binding does not seem to play a significant role in the regulation of urate homeostasis.
authors.affiliation: University of Florida, 1600 SW Archer Road, PO Box 100224, Gainesville, FL 32610-0224, USA. gerscms@medicine.ufl.edu
authors.forename: Michael S
authors.initials: MS
authors.lastname: Gersch
authors.forename: Yuri Y
authors.initials: YY
authors.lastname: Sautin
authors.forename: Christine M
authors.initials: CM
authors.lastname: Gersch
authors.forename: George
authors.initials: G
authors.lastname: Henderson
authors.forename: Lise
authors.initials: L
authors.lastname: Bankir
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Johnson
mesh_terms: D000418:Albumins / Q000378:metabolism; D015153:Blotting, Western; D002853:Chromatography, Liquid; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D047468:Immunoprecipitation; D008297:Male; D013058:Mass Spectrometry; D009088:Mucoproteins / Q000378:metabolism*; D011485:Protein Binding / Q000502:physiology; D014527:Uric Acid / Q000378:metabolism*; D058949:Uromodulin
chemical_list: D000418:Albumins; D009088:Mucoproteins; C548612:UMOD protein, human; D058949:Uromodulin; D014527:Uric Acid