Phosphorin, A Phosphate-Binding Hydrophobic Protein Isolated from Renal Brush Border Membranes

  • Ralph J. Kessler
  • Duke A. Vaughn
  • Christian Schäli
  • Darrell D. Fanestil
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 208)


Reabsorption of inorganic phosphate (Pi) by the renal proximal tubule occurs from the tubular fluid across the brush border membrane into the cell interior by a Na+-dependent co-transport system. A number of the features of this Na+-Pi symport system have been documented by earlier workers(1,2). These include a description of the kinetic parameters and of the alterations produced by in vivo manipulation of dietary phosphate(3) or vitamin D(4) or by parathyroid hormone status(5). However, the molecular constituent or constituents of this Na+-Pi symporter have not been identified. We summarize here some features of a putative constituent of the Na+-Pi symporter, a proteolipid that can be extracted from renal brush borders. We have called this proteolipid “phosphorin” because it binds Pi with selectivity and high affinity and because it is located in brush borders that conduct Na+-Pi symport. Although our working hypothesis is that phosphorin might be a constituent of the Na+-Pi symporter, firm evidence for such a role for phosphorin remains to be advanced.


Divalent Metal Phosphate Binding Brush Border Membrane Vesicle Dietary Phosphate Renal Brush Border Membrane 


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  1. 1.
    N. Hoffman, M. Theis and R. Kinne. Phosphate Transport by Isolated Renal Brush Border Vesicles. Eur. J. Physiol. 362: 147–156 (1976).CrossRefGoogle Scholar
  2. 2.
    L. Cheng and B. Sacktor. Sodium Gradient-Dependent Phosphate Transport in Renal Brush Border Membrane Vesicles. J. Biol. Chem. 256: 1556 (1981)Google Scholar
  3. 3.
    S.A. Kempson, S.V. Shah, P.G. Wenness, T. Berndt, P.H. Lee, L.H. Smith, F.G. Knox and T.P. Dousa. Renal Brush Border Membranes Adaption to Phosphorus Deprivation: Effects of Fasting Versus Low-Phosphorus Diet. Kidney Int. 18: 36 (1980)CrossRefGoogle Scholar
  4. 4.
    D.B. N. Lee, M.W. Walling, J.G. Siliss and J.W. Coburn. Calcium and Inorganic Phosphate Transport in Rat Colon: Dissociated Response to 1,25-Dihydroxyvitamin D3. J. Clin. Invest. 65: 1326 (1980)CrossRefGoogle Scholar
  5. 5.
    R. Stoll, R. Kinne, H. Murer, H. Fleisch and J.P. Bonjour. Phosphate Transport by Rat Renal Brush Border Membrane Vesicles: Influence of Dietary Phosphate, Thyroparathyroidectomy and 1,25-Dihydroxyvitamin D3. Pfluegers Arch. Eur. J. Physiol. 380: 47–52 (1979)CrossRefGoogle Scholar
  6. 6.
    J. Folch-Pi and M.B. Lees. Proteolipids, a New Type of Tissue Lipoproteins: Their Isolation from Brain. J. Biol. Chem. 191: 807 (1951)Google Scholar
  7. 7.
    A.G. Booth and A.J. Kenny. A Rapid Method for the Preparation of Microvilli from Rabbit Kidney. Biochem. J. 142: 575 (1974)Google Scholar
  8. 8.
    R.J. Kessler, D.A. Vaughn and D.D. Fanestil. Phosphate-binding Proteo-lipid from Brush Border. J. Biol. Chem. 257: 14311 (1982)Google Scholar
  9. 9.
    R.J. Kessler and D.A. Vaughn. Divalent Metal is Required for Both Phosphate Transport and Phosphate Binding to Phosphorin, a Proteolipid Isolated from Brush Border Membrane Vesicles. J. Biol. Chem. 259: 9059 (1984)Google Scholar
  10. 10.
    C. Schäli, D.A. Vaughn and D.D. Fanestil. Enzymatic Removal of Alkaline Phosphatase from Renal Brush-Border Membranes. Effect on Phosphate Transport and on Phosphate Binding. Biochim. Biophys. Acta 769: 277 (1984)CrossRefGoogle Scholar
  11. 11.
    A.N. K. Yusufi, M.G. Low, S.T. Turner and T.P. Dousa. Selective Removal of Alkaline Phosphatase from Renal Brush-Border Membrane and Sodium-Dependent Brush-Border Membrane Transport. J. Biol. Chem. 258: 5695 (1983)Google Scholar
  12. 12.
    C. Schäli and D.D. Fanestil. Solubilization and Reconstitution of the Renal Phosphate Transporter. Biochim. Biophys. Acta (in press)Google Scholar

Copyright information

© Plenum Press, New York 1986

Authors and Affiliations

  • Ralph J. Kessler
    • 1
  • Duke A. Vaughn
    • 1
  • Christian Schäli
    • 1
  • Darrell D. Fanestil
    • 1
  1. 1.Department of Medicine, Division of Nephrology, M-023BUniversity of California, San DiegoLa JollaUSA

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