HCO3-transporter NBCn2 (SLC4A10) plays critically important role in the central nervous system (CNS).Dysfunction of SLC4A10 is associated with a series of mental disorders.However, little is known about the mechanisms underlying the regulation of SLC4A10 expression.Here, we demonstrated by luciferase reporter assay that Slc4a10 contains two alternative promoters permitting the expression of two types of NBCn2 with distinct extreme amino terminus (Nt).Western blotting data showed that NBCn2 proteins with the originally described Nt are specifically expressed in CNS.In contrast, those with the novel Nt are specifically expressed in the kidney and intestine, the first report that NBCn2 proteins are expressed in organs other than the brain.We conclude that the usage of alternative promoters in Slc4a10 expression is regulated tissue-specifically.Our study shed important new light in studying the physiology of NBCn2.