Delpire E, Rauchman M I, Beier D R, Hebert S C, Gullans S R
Harvard Center for Study of Kidney Disease, Renal Division, Harvard Medical School, Boston, Massachusetts.
J Biol Chem. 1994 Oct 14;269(41):25677-83.
Electroneutral Na(+)-K(+)-2Cl- cotransporters represent one of the major routes for Cl- movement in epithelia. A secretory form of the cotransporter has been described in the basolateral membrane of a variety of epithelia from fish to mammals. We isolated a putative bumetanide-sensitive Na(+)-K(+)-2Cl- cotransporter cDNA, BSC2, from mIMCD-3 cells. Northern analysis indicates that in contrast to BSC1, the recently cloned renal-specific apical isoform of the cotransporter, BSC2 is expressed in secretory epithelia and thus appears to represent the basolateral isoform. Furthermore, BSC2 is also expressed in non-polarized cells, such as red cells and myocytes. Sequence comparison and chromosome localization demonstrate that BSC2 and BSC1 are different genes that diverged before the evolution of vertebrates.
电中性钠-钾-2氯协同转运体是上皮细胞中氯离子移动的主要途径之一。从鱼类到哺乳动物，多种上皮细胞的基底外侧膜中已描述了该协同转运体的一种分泌形式。我们从mIMCD - 3细胞中分离出一种假定的布美他尼敏感型钠-钾-2氯协同转运体cDNA，即BSC2。Northern分析表明，与最近克隆的肾脏特异性顶端异构体BSC1不同，BSC2在分泌上皮细胞中表达，因此似乎代表基底外侧异构体。此外，BSC2也在非极化细胞中表达，如红细胞和心肌细胞。序列比较和染色体定位表明，BSC2和BSC1是不同的基因，在脊椎动物进化之前就已分化。
