Abnormal proximal tubule apical membrane protein composition in X-linked hypophosphatemic mice

Douglas M. Ford, Bruce Molitoris

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

The hypophospha-temic (Hyp) mouse is characterized by an isolated X-linked defect in proximal tubular phosphate (Pi) reabsorption associated with a decreased maximum velocity ( Vmax) and a normal affinity (Km). To directly investigate the underlying cellular defect proximal tubular brush-border membranes (BBM) from normal control (Con) and Hyp male littermates were examined for differences in cholesterol content, total and individual phospholipid composition, phospholipid incorporation rates, membrane fluidity, and by two-dimensional sodium dodecyl sulfate (SDS)-polyacrylamide protein electrophoresis. The cholesterol content, total and individual phospholipid profiles, phospholipid incorporation rates, and membrane fluidity of Con and Hyp BBM samples were comparable. However, the two-dimensional gel electrophoreses of Con and Hyp BBM proteins, run simultaneously under identical conditions, revealed a protein with an apparent abnormal isoelectric migration pattern in Hyp BBM samples. This protein had an apparent molecular weight 56,000 and an apparent pI of 7.2 and was consistantly evident on Hyp gels (n = 3) but not on Con gels (n = 3). The appearance of this protein band was associated with a diminution in staining of a control protein of comparable apparent molecular weight but markedly lower apparent pi.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Renal Fluid and Electrolyte Physiology
Volume260
Issue number3 29-3
StatePublished - 1991
Externally publishedYes

Fingerprint

Microvilli
Membrane Proteins
Phospholipids
Membrane Fluidity
Gels
Proteins
Membranes
Molecular Weight
Cholesterol
Sodium Dodecyl Sulfate
Electrophoresis
Phosphates
Staining and Labeling

Keywords

  • Phosphaturia
  • Two-dimensional polyacrylamide gel electrophoresis
  • X-linked hypophosphatemic rickets

ASJC Scopus subject areas

  • Physiology

Cite this

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abstract = "The hypophospha-temic (Hyp) mouse is characterized by an isolated X-linked defect in proximal tubular phosphate (Pi) reabsorption associated with a decreased maximum velocity ( Vmax) and a normal affinity (Km). To directly investigate the underlying cellular defect proximal tubular brush-border membranes (BBM) from normal control (Con) and Hyp male littermates were examined for differences in cholesterol content, total and individual phospholipid composition, phospholipid incorporation rates, membrane fluidity, and by two-dimensional sodium dodecyl sulfate (SDS)-polyacrylamide protein electrophoresis. The cholesterol content, total and individual phospholipid profiles, phospholipid incorporation rates, and membrane fluidity of Con and Hyp BBM samples were comparable. However, the two-dimensional gel electrophoreses of Con and Hyp BBM proteins, run simultaneously under identical conditions, revealed a protein with an apparent abnormal isoelectric migration pattern in Hyp BBM samples. This protein had an apparent molecular weight 56,000 and an apparent pI of 7.2 and was consistantly evident on Hyp gels (n = 3) but not on Con gels (n = 3). The appearance of this protein band was associated with a diminution in staining of a control protein of comparable apparent molecular weight but markedly lower apparent pi.",
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TY - JOUR

T1 - Abnormal proximal tubule apical membrane protein composition in X-linked hypophosphatemic mice

AU - Ford, Douglas M.

AU - Molitoris, Bruce

PY - 1991

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N2 - The hypophospha-temic (Hyp) mouse is characterized by an isolated X-linked defect in proximal tubular phosphate (Pi) reabsorption associated with a decreased maximum velocity ( Vmax) and a normal affinity (Km). To directly investigate the underlying cellular defect proximal tubular brush-border membranes (BBM) from normal control (Con) and Hyp male littermates were examined for differences in cholesterol content, total and individual phospholipid composition, phospholipid incorporation rates, membrane fluidity, and by two-dimensional sodium dodecyl sulfate (SDS)-polyacrylamide protein electrophoresis. The cholesterol content, total and individual phospholipid profiles, phospholipid incorporation rates, and membrane fluidity of Con and Hyp BBM samples were comparable. However, the two-dimensional gel electrophoreses of Con and Hyp BBM proteins, run simultaneously under identical conditions, revealed a protein with an apparent abnormal isoelectric migration pattern in Hyp BBM samples. This protein had an apparent molecular weight 56,000 and an apparent pI of 7.2 and was consistantly evident on Hyp gels (n = 3) but not on Con gels (n = 3). The appearance of this protein band was associated with a diminution in staining of a control protein of comparable apparent molecular weight but markedly lower apparent pi.

AB - The hypophospha-temic (Hyp) mouse is characterized by an isolated X-linked defect in proximal tubular phosphate (Pi) reabsorption associated with a decreased maximum velocity ( Vmax) and a normal affinity (Km). To directly investigate the underlying cellular defect proximal tubular brush-border membranes (BBM) from normal control (Con) and Hyp male littermates were examined for differences in cholesterol content, total and individual phospholipid composition, phospholipid incorporation rates, membrane fluidity, and by two-dimensional sodium dodecyl sulfate (SDS)-polyacrylamide protein electrophoresis. The cholesterol content, total and individual phospholipid profiles, phospholipid incorporation rates, and membrane fluidity of Con and Hyp BBM samples were comparable. However, the two-dimensional gel electrophoreses of Con and Hyp BBM proteins, run simultaneously under identical conditions, revealed a protein with an apparent abnormal isoelectric migration pattern in Hyp BBM samples. This protein had an apparent molecular weight 56,000 and an apparent pI of 7.2 and was consistantly evident on Hyp gels (n = 3) but not on Con gels (n = 3). The appearance of this protein band was associated with a diminution in staining of a control protein of comparable apparent molecular weight but markedly lower apparent pi.

KW - Phosphaturia

KW - Two-dimensional polyacrylamide gel electrophoresis

KW - X-linked hypophosphatemic rickets

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