Calmodulin-regulated, ATP-driven calcium transport by basolateral membranes of rat small intestine.
Calmodulin-regulated, ATP-driven calcium transport by basolateral membranes of rat small intestine.
复制标题
钙调蛋白调节、ATP 驱动的大鼠小肠基底外侧膜的钙转运。
DOI：
10.1016/s0021-9258(19)68719-3
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发表时间：
1981
期刊：
影响因子：
--
通讯作者：
Joan E. Popovitch
中科院分区：
文献类型：
--
作者：
Small Intestine;Hugh N. NellansS;Joan E. Popovitch
利用快速过滤技术研究了大鼠小肠基底外侧质膜囊泡中富集的膜组分对钙的摄取。钙的积累由ATP刺激并由钙离子载体A23187释放。动力学研究表明，ATP驱动的摄取的半最大刺激的钙浓度为28 nM。运输受到寡霉素和哇巴因的最低限度抑制，但镧使其减少40%，50 μ M钒酸盐使其消失。钙调节蛋白钙调素以剂量依赖性方式刺激ATP依赖性钙摄取。钙调素增加最大转运速率和转运机制的钙亲和力。这些结果与肠上皮细胞基底侧质膜中存在ATP依赖性、钙调素调节的钙转运机制一致，并表明钙调素除了控制胞浆钙水平外，还可调节跨上皮钙吸收。
Uptake of calcium by a membrane fraction enriched in basolateral plasma membrane vesicles from rat small intestine has been investigated using a rapid filtration technique. Calcium accumulation is stimulated by ATP and released by the calcium ionophore A23187. Kinetic studies indicate a calcium concentration of 28 nM for half-maximal stimulation of ATP-driven uptake. Transport is minimally inhibited by oligomycin and ouabain but is reduced 40% by lanthanum and abolished by 50 microM vanadate. The ATP-dependent calcium uptake is stimulated by the calcium regulatory protein, calmodulin, in a dose-dependent fashion. Calmodulin increases both the maximal transport rate and the calcium affinity of the transport mechanism. These results are consistent with the existence of an ATP-dependent, calmodulin-regulated calcium transport mechanism in the basolateral plasma membrane of intestinal epithelial cells, and suggests that calmodulin may modulate transepithelial calcium absorption in addition to controlling cytosolic calcium levels.