Biochemical and Biophysical Research Communications
Localization of NBC-1 variants in human kidney and renal cell carcinoma
Section snippets
Materials and methods
Tissues. Human kidneys were obtained with full informed consent from three patients (age: 60, 71, and 80 years old) who underwent the total nephrectomy for RCC. The histological analysis confirmed that all these tumors were of common type, clear cell subtype. Both histologically normal tissues and cancer tissues were immediately frozen in liquid nitrogen for Western blot analysis or processed for immunohistochemical analysis.
Western blot analysis. Western blot analysis was performed as
Western blot analysis
To determine the dominant NBC-1 variant(s) expressed in human kidney and RCC tissues, we first performed Western blot using the variant-specific antibodies. As shown in Fig. 1, the anti-kNBC-1 antibody yielded a clear band of ∼145 kDa from the normal renal tissues. In all three RCC tissues, a similar band was also detected by the anti-kNBC-1 antibody. By contrast, the anti-pNBC-1 antibody failed to yield a clear band from both normal kidney and RCC tissues (data not shown), though this antibody
Discussion
The anti-peptide antibodies used in the present study were raised against the N-terminal regions of human kNBC-1 and pNBC-1. The specificity of these antibodies was confirmed by the expression study on ECV304 cells [11]. Another NBC-1-related isoform, rb2NBC-1, has the novel C-terminal region, but its N-terminal region is identical to that of pNBC-1 [5]. Therefore rb2NBC-1 is expected to be detected by the anti-pNBC-1 antibody, though its human counterpart has not been cloned so far.
Acknowledgements
This study was in part supported by Grants 12671024 and 14571013 from the Ministry of Education, Science and Culture of Japan. Anti-NBC-1 antibodies were supplied by Kumamoto Immunochemical Laboratory (Kumamoto, Japan).
References (25)
- et al.
Cloning and functional expression of a human kidney Na+:HCO3− cotransporter
J. Biol. Chem.
(1997) - et al.
Molecular cloning, chromosomal localization, tissue distribution, and functional expression of the human pancreatic sodium bicarbonate cotransporter
J. Biol. Chem.
(1998) - et al.
Structural organization of the human NBC1 gene: kNBC1 is transcribed from an alternative promoter in intron 3
Gene
(2000) - et al.
Expression cloning and characterization of a renal electrogenic Na+/HCO3− cotransporter
Nature
(1997) - et al.
An electrogenic Na+–HCO3− cotransporter (NBC) with a novel COOH-terminus, cloned from rat brain
Am. J. Physiol. Cell Physiol.
(2000) - et al.
Electrogenic Na+/HCO3− cotransporters: cloning and physiology
Annu. Rev. Physiol.
(1999) - et al.
Cloning and functional expression of rNBC, an electrogenic Na+–HCO3− cotransporter from rat kidney
Am. J. Physiol.
(1998) - et al.
Cloning and characterization of a human electrogenic Na+–HCO3− cotransporter isoform (hhNBC)
Am. J. Physiol.
(1999) - et al.
Mutations in SLC4A4 cause permanent isolated proximal renal tubular acidosis with ocular abnormalities
Nat. Genet.
(1999) - et al.
Unraveling the molecular pathogenesis of isolated proximal renal tubular acidosis
J. Am. Soc. Nephrol.
(2002)
Molecular basis of ocular abnormalities associated with proximal renal tubular acidosis
J. Clin. Invest.
Novel nonsense mutation in the Na+/HCO3− cotransporter gene (SLC4A4) in a patient with permanent isolated proximal renal tubular acidosis and bilateral glaucoma
J. Am. Soc. Nephrol.
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These authors equally contributed to this study.