Developmentally regulated 75-kilodalton protein expressed in LLC-PK1 cultures is a component of the renal Na+/glucose cotransport system.
Developmentally regulated 75-kilodalton protein expressed in LLC-PK1 cultures is a component of the renal Na+/glucose cotransport system.
复制标题
LLC-PK1 培养物中表达的发育调节的 75 千道尔顿蛋白是肾脏钠/葡萄糖协同转运系统的组成部分。
DOI：
10.1002/jcb.240400109
复制
发表时间：
1989
影响因子：
4
通讯作者：
Lever,JE
中科院分区：
文献类型：
--
作者：
Wu,JS;Lever,JE
Na+/D-葡萄糖共转运是仅在肾脏近端小管和小肠中表达的次级主动葡萄糖转运机制。识别猪肾刷状缘膜Na+/葡萄糖同向转运体的单克隆抗体也识别从高度分化的LLC-PK 1培养物（猪肾近端小管来源的上皮细胞系）分离的顶膜中的75-kD蛋白。通过高压液相色谱法从溶解的LLC-PK 1顶端膜中富集75-kD抗原。在与运输活性的表达相关的汇合单层的发展后，同向转运体抗原变得明显的顶膜表面上。用分化诱导剂β-二乙酰胺长期处理培养物伴随着同向转运体抗原表达的显著增加，如通过Western印迹分析定量检测和通过免疫荧光染色定性检测。诱导剂处理后，同向转运体阳性细胞的数量显著增加，如分化调节表达所预测的。这些结果确定了一个75 kD的蛋白质作为细胞培养物中表达的发育调节的肾脏Na+/葡萄糖同向转运体的组分。
Na+/D‐glucose symport is a secondary active glucose transport mechanism expressed only in kidney proximal tubule and in small intestine. A monoclonal antibody that recognized the Na+/glucose symporter of pig renal brush border membranes also recognized a 75‐kD protein in apical membranes isolated from highly differentiated LLC‐PK1cultures, an epithelial cell line of pig renal proximal tubule origin. The 75‐kD antigen was enriched from solubilized LLC‐PK1apical membranes by means of high‐pressure liquid chromatography. The symporter antigen became apparent on the apical membrane surface after the development of a confluent monolayer in correlation with the expression of transport activity. Long‐term treatment of cultures with the differentiation inducer hexamethylene bisacetamide was accompanied by a dramatically increased expression of the symporter antigen as detected quantitatively by Western blot analysis and qualitatively by immunofluorescence staining. The number of symporter‐positive cells was dramatically increased after inducer treatment as predicted for differentiation‐regulated expression. These results identify a 75‐kD protein as a component of a developmentally regulated renal Na+/glucose symporter expressed in cell culture.