Myosin 1b Regulates Amino Acid Transport by Associating Transporters with the Apical Plasma Membrane of Kidney Cells.
Myosin 1b Regulates Amino Acid Transport by Associating Transporters with the Apical Plasma Membrane of Kidney Cells.
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DOI：
10.1371/journal.pone.0138012
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Coluccio LM
中科院分区：
文献类型：
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作者：
Komaba S;Coluccio LM
肾近曲小管 (PT) 细胞顶端质膜 (APM) 刷状缘中的氨基酸转运蛋白 (AATers) 介导氨基酸转运 (AAT)。我们发现膜相关的 I 类肌球蛋白肌球蛋白 1b (Myo1b) 定位于 PT 的顶端刷状缘膜。在源自 PT 的负鼠肾 (OK) 3B/2 上皮细胞中，表达大鼠 Myo1b-GFP，与表达的小鼠 V5 标记的 SIT1 (SIT1-V5) 共定位于修补的微绒毛中，后者介导 OK 细胞中的中性氨基酸转运。慢病毒介导的负鼠 Myo1b 特异性 shRNA 递送导致 Myo1b 表达敲低 (kd)、APM 处 SIT1-V5 减少（根据定位研究确定）以及中性 AAT 减少（根据放射性摄取测定确定）。根据罗丹明鬼笔环肽染色测定，Myo1b kd 对 Pi 转运没有影响，也没有微绒毛结构的明显变化。这些研究首次明确了 Myo1b 的生理作用，即通过调节 AATers 与 APM 的关联来调节肾脏 AAT。
Amino acid transporters (AATers) in the brush border of the apical plasma membrane (APM) of renal proximal tubule (PT) cells mediate amino acid transport (AAT). We found that the membrane-associated class I myosin myosin 1b (Myo1b) localized at the apical brush border membrane of PTs. In opossum kidney (OK) 3B/2 epithelial cells, which are derived from PTs, expressed rat Myo1b-GFP colocalized in patched microvilli with expressed mouse V5-tagged SIT1 (SIT1-V5), which mediates neutral amino acid transport in OK cells. Lentivirus-mediated delivery of opossum Myo1b-specific shRNA resulted in knockdown (kd) of Myo1b expression, less SIT1-V5 at the APM as determined by localization studies, and a decrease in neutral AAT as determined by radioactive uptake assays. Myo1b kd had no effect on Pi transport or noticeable change in microvilli structure as determined by rhodamine phalloidin staining. The studies are the first to define a physiological role for Myo1b, that of regulating renal AAT by modulating the association of AATers with the APM.