title: Distribution of NBCn2 (SLC4A10) splice variants in mouse brain.
abstract: The five known Na-coupled HCO(3)(-) transporters (NCBTs) of the solute carrier 4 (SLC4) family play important roles in pH regulation and transepithelial HCO(3)(-) transport. Nearly all of the NCBTs have multiple splice variants. One particular NCBT, the electroneutral Na/HCO(3)(-) cotransporter NBCn2 (SLC4A10), which is predominantly expressed in brain, has three known splice variants-NBCn2-A, -B, and -C-as well as a potential variant-D. It is important to know the tissue-specific expression of the splice variants for understanding the physiological roles of NBCn2 in central nervous system. In the present study, we developed three novel rabbit polyclonal antibodies against NBCn2: (1) anti-ABCD, which recognizes all four variants; (2) anti-BD, which recognizes NBCn2-B and -D; (3) anti-CD, which recognizes NBCn2-C and -D. By western blotting, we examined the expression and distribution of NBCn2 splice variants in five brain regions: cerebral cortex, subcortex, cerebellum, hippocampus, and medulla. The expression pattern revealed with anti-ABCD is distinct from those revealed with anti-BD and anti-CD. Moreover, by using immunoprecipitation in combination with western blotting, we demonstrate that NBCn2-D does indeed exist and that it is predominantly expressed in subcortex, to a lesser extent in medulla, but at very low levels in cortex, cerebellum, and hippocampus. NBCn2-A may be the dominant variant in mouse brain as a whole, and may also dominate in cerebral cortex, cerebellum, and hippocampus. Immunohistochemistry with anti-ABCD shows that NBCn2 is highly expressed in choroid plexus, cortex, molecular layer of cerebellum, hippocampus, and some specific regions of the brainstem.
authors.affiliation: Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA. liuying@mail.hust.edu.cn
authors.forename: Y
authors.initials: Y
authors.lastname: Liu
authors.forename: K
authors.initials: K
authors.lastname: Xu
authors.forename: L M
authors.initials: LM
authors.lastname: Chen
authors.forename: X
authors.initials: X
authors.lastname: Sun
authors.forename: M D
authors.initials: MD
authors.lastname: Parker
authors.forename: M L
authors.initials: ML
authors.lastname: Kelly
authors.forename: J C
authors.initials: JC
authors.lastname: LaManna
authors.forename: W F
authors.initials: WF
authors.lastname: Boron
mesh_terms: D017398:Alternative Splicing; D000818:Animals; D027321:Anion Transport Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D000918:Antibody Specificity; D017920:Antiporters / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D001921:Brain / Q000378:metabolism*; D027963:Chloride-Bicarbonate Antiporters / Q000096:biosynthesis*; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D047468:Immunoprecipitation; D051379:Mice; D008810:Mice, Inbred C57BL; D011817:Rabbits; D027982:Sodium-Bicarbonate Symporters / Q000096:biosynthesis*; D014981:Xenopus
chemical_list: D027321:Anion Transport Proteins; D017920:Antiporters; D027963:Chloride-Bicarbonate Antiporters; C425809:SLC4A11 protein, human; C526208:Slc4a10 protein, mouse; D027982:Sodium-Bicarbonate Symporters