Preferential expression of plasmalemmal K-dependent Na+/Ca2+ exchangers in neurons versus astrocytes.
Preferential expression of plasmalemmal K-dependent Na+/Ca2+ exchangers in neurons versus astrocytes.
复制标题
与星形胶质细胞相比，神经元中质膜 K 依赖性 Na /Ca2 交换剂的优先表达。
DOI：
10.1097/00001756-200208270-00008
复制
发表时间：
2002
期刊：
影响因子：
1.7
通讯作者：
Lytton,Jonathan
中科院分区：
文献类型：
--
作者：
Kiedrowski,Lech;Czyz,Aneta;Li,Xiao-Fang;Lytton,Jonathan
脑组织表达多种不同亚型的质膜K依赖性(NCKX)和非K非依赖性(NCX)Na+/Ca2+交换器。每种异构体的生理功能目前尚不清楚。因此，在这项研究中，我们比较了NCKX和NCX转录本在小脑颗粒细胞原代培养和星形胶质细胞中的表达。Northern印迹分析表明，颗粒细胞表达NCKX2、NCKX3、NCKX4和NCX3，而星形胶质细胞主要表达NCX1。与这一分子特征相一致的是，在钠颗粒细胞中，有相当一部分的45Ca2+积累，而在星形胶质细胞中则不是，依赖于外部K+。这是首次证明来自中枢神经系统的神经元具有天然的NCKX活性。我们的数据提示，NCKX亚型的表达可能与神经元独特的钙稳态需求相对应。
Numerous isoforms of plasmalemmal K-dependent (NCKX) and K-independent (NCX) Na+/Ca 2+ exchangers are expressed in the brain. The physiological functions of each isoform are presently unknown. Therefore, in this study, we compared expression of NCKX and NCX transcripts between primary cultures of cerebellar granule cells, and astrocytes. Northern blot analysis showed that granule cells expressed NCKX2, NCKX3, NCKX4 and NCX3, whereas astrocytes expressed primarily NCX1. Consistent with this molecular characterization, a significant fraction of 45 Ca 2+ accumulation in Na-loaded granule cells, but not in astrocytes, depended on external K+. This is the first demonstration of native NCKX activity in neurons derived from the central nervous system. Our data suggest that NCKX isoform expression may correspond to the unique Ca 2+ homeostasis requirements of neurons.