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Journal article

Cloning and expression of cDNA for a Na/Pi cotransport system of kidney cortex.

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  • 1991-11-01
Published in:
  • Proceedings of the National Academy of Sciences of the United States of America. - 1991
Amino Acid Sequence
Animals
Base Sequence
Blotting, Northern
Carrier Proteins
Cloning, Molecular
DNA
Gene Expression
Kidney Cortex
Membrane Glycoproteins
Molecular Sequence Data
Phosphates
RNA, Messenger
Rabbits
Sequence Alignment
Sodium
Sodium-Phosphate Cotransporter Proteins
Solubility
Symporters
Xenopus laevis
English A cDNA library from rabbit kidney cortex was screened for expression of Na-dependent transport of phosphate (Pi) using Xenopus laevis oocytes as an expression system. A single clone was eventually isolated (designated NaPi-1) that stimulated expression of Na/Pi cotransport approximately 700-fold compared to total mRNA. The predicted sequence of the Na/Pi cotransporter consists of 465 amino acids (relative molecular mass, 51,797); hydropathy profile predictions suggest six (possibly eight) membrane-spanning segments. In vitro translation of NaPi-1/complementary RNA in the presence of pancreatic microsomes indicated NaPi-1 to be a glycosylated protein; four potential N-glycosylation sites are present in the amino acid sequence. Northern blot analysis demonstrated the presence of NaPi-1/mRNA in kidney cortex and liver; no hybridization signal was obtained with mRNA from other tissues (including small intestine). Kinetic analysis of Na/Pi cotransport expressed by NaPi-1/complementary RNA demonstrated characteristics (sodium interaction) similar to those observed in cortical apical membranes. The alignment of 5 amino acid residues (Gly342/Ala381-Xaa-Xaa-Xaa-Xaa-Leu386-Xaa-Xaa-Xaa-P ro390- Arg391) is consistent with a motif proposed for Na-dependent transport systems. We conclude that we have cloned a cDNA for a Na/Pi cotransport system present in rabbit kidney cortex.
Language
  • English
Open access status
bronze
Identifiers
Persistent URL
https://sonar.rero.ch/global/documents/237860
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