Distribution of NBCn2 (SLC4A10) splice variants in mouse brain.
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.
Liu
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Y
Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA. liuying@mail.hust.edu.cn
Xu
K
K
Chen
L M
LM
Sun
X
X
Parker
M D
MD
Kelly
M L
ML
LaManna
J C
JC
Boron
W F
WF
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
D027321:Anion Transport Proteins; D017920:Antiporters; D027963:Chloride-Bicarbonate Antiporters; C425809:SLC4A11 protein, human; C526208:Slc4a10 protein, mouse; D027982:Sodium-Bicarbonate Symporters