Abstract
The multi-subunit H+-ATPase pump is present at particularly high density on the apical (luminal) surface of α-intercalated cells of the cortical collecting duct of the distal nephron, where vectorial proton transport is required for urinary acidification1. The complete subunit composition of the apical ATPase, however, has not been fully agreed upon. Functional failure of α-intercalated cells results in a group of disorders, the distal renal tubular acidoses (dRTA), whose features include metabolic acidosis accompanied by disturbances of potassium balance, urinary calcium solubility, bone physiology and growth2. Mutations in the gene encoding the B-subunit of the apical pump (ATP6B1) cause dRTA accompanied by deafness3. We previously localized a gene for dRTA with preserved hearing to 7q33–34 (ref. 4). We report here the identification of this gene, ATP6N1B, which encodes an 840 amino acid novel kidney-specific isoform of ATP6N1A, the 116-kD non-catalytic accessory subunit of the proton pump. Northern-blot analysis demonstrated ATP6N1B expression in kidney but not other main organs. Immunofluorescence studies in human kidney cortex revealed that ATP6N1B localizes almost exclusively to the apical surface of α-intercalated cells. We screened nine dRTA kindreds with normal audiometry that linked to the ATP6N1B locus, and identified different homozygous mutations in ATP6N1B in eight. These include nonsense, deletion and splice-site changes, all of which will truncate the protein. Our findings identify a new kidney-specific proton pump 116-kD accessory subunit that is highly expressed in proton-secreting cells in the distal nephron, and illustrate its essential role in normal vectorial acid transport into the urine by the kidney.
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References
Gluck, S.L. et al. Physiology and biochemistry of the kidney vacuolar H+-ATPase. Annu. Rev. Physiol. 58, 427–445 (1996).
Bastani. B. & Gluck, S.L. New insights into the pathogenesis of distal renal tubular acidosis. Miner. Electrolyte Metab. 22, 396–409 (1996).
Karet, F.E. et al. Mutations in the gene encoding the B1 subunit of H+-ATPase cause renal tubular acidosis with sensorineural deafness. Nature Genet. 21, 84–90 (1999).
Karet, F.E. et al. Localization of a gene for autosomal recessive distal renal tubular acidosis with normal hearing (rdRTA2) to 7q33–34. Am. J. Hum. Genet. 65, 1656–1665 (1999).
Brody, L.C. et al. Construction of a transcription map surrounding the BRCA1 locus of human chromosome 17. Genomics 25, 238–247 (1995).
Peng, S.B., Crider, B.P., Xie, X.S. & Stone, D.K. Alternative mRNA splicing generates tissue-specific isoforms of 116-kDa polypeptide of vacuolar proton pump. J. Biol. Chem. 269, 17262–17266 (1994).
Li, Y.P., Chen, W. & Stashenko, P. Molecular cloning and characterization of a putative novel human osteoclast-specific 116 kDa vacuolar proton pump subunit. Biochem. Biophys. Res. Commun. 26, 813–21 (1996).
Heinemann, T. et al. Genomic organization of the gene coding for TIRC7, a novel membrane protein essential for T cell activation. Genomics 57, 398–406 (1999).
Nelson, R.D. et al. Selectively amplified expression of an isoform of the vacuolar H+-ATPase 56-kilodalton subunit in renal intercalated cells. Proc. Natl Acad. Sci. USA 89, 3541–3545 (1992).
Brown, D. Targeting of membrane transporters in renal epithelia: when cell biology meets physiology. Am. J. Physiol. 278, F192–F201 (2000).
Nilsson, T. & Warren, G. Retention and retrieval in the endoplasmic reticulum and the Golgi apparatus. Curr. Opin. Cell Biol. 6, 517–521 (1994).
Gluck, S. & Caldwell, J. Immunoaffinity purification and characterization of vacuolar H+ATPase from bovine kidney. J. Biol. Chem. 262, 15780–15789 (1987).
Gillespie, J. et al. The vacuolar H+-translocating ATPase of renal tubules contains a 115-kD glycosylated subunit. FEBS Lett. 282, 69–72 (1991).
Leng, X.H., Manolson, M., Liu, Q. & Forgac, M. Site-directed mutagenesis of the 100-kDa subunit (Vph1p) of the yeast vacuolar (H+)-ATPase. J. Biol. Chem. 271, 22487–22493 (1996).
Leng, X.H., Manolson, M.F. & Forgac, M. Function of the COOH-terminal domain of Vph1p in activity and assembly of the yeast V-ATPase. J. Biol. Chem. 273, 6717–6723 (1998).
Bell, G., Karam, J. & Rutter, W. Polymorphic DNA region adjacent to the 5′-end of the human insulin gene. Proc. Natl Acad. Sci. USA 78, 5759–5763 (1981).
Mansfield, T.A. et al. Multilocus linkage of familial hyperkalaemia and hypertension, pseudohypoaldosteronism type II, to chromosomes 1q31–42 and 17p11–q21. Nature Genet. 16, 202–205 (1997).
Kruglyak, L., Daly, M.J., Reeve-Daly, M.P. & Lander, E.S. Parametric and nonparametric linkage analysis: a unified multipoint approach. Am. J. Hum. Genet. 58, 1347–1363 (1996).
Munroe, D.J. et al. IRE-bubble PCR: a rapid method for efficient and representative amplification of human genomic DNA sequences from complex sources. Genomics 19, 506–514 (1994).
Shimkets, R.A. et al. Liddle's syndrome: heritable human hypertension caused by mutations in the β-subunit of the epithelial sodium channel. Cell 79, 407–414 (1994).
Frattini, A. et al. Defects in TCIRG1 subunit of the vacuolar proton pump are responsible for a subset of human autosomal recessive osteopetrosis. Nature Genet. 25, 343–346 (2000).
Acknowledgements
We thank patients and their families for contributing; K. Finberg, D. Fritz and J. Grover for technical assistance; C. Nelson-Williams for management of the DNA database; F.L. Raymond for helpful discussion, and L.-C. Tsui for support. K.A.C. is an investigator of the N.I.H. Medical Scientist Training Program. R.P.L. is an investigator of the Howard Hughes Medical Institute. This work was supported by the Wellcome Trust, of which F.E.K. is a Senior Clinical Research Fellow, and the Medical Research Council of Canada, of which S.W.S. is a Scholar.
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Smith, A., Skaug, J., Choate, K. et al. Mutations in ATP6N1B, encoding a new kidney vacuolar proton pump 116-kD subunit, cause recessive distal renal tubular acidosis with preserved hearing. Nat Genet 26, 71–75 (2000). https://doi.org/10.1038/79208
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DOI: https://doi.org/10.1038/79208
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