...
首页> 外文期刊>Molecular and Cellular Biology >Phosphatidylinositol 3-Phosphate [PtdIns(3)P] Is Generated at the Plasma Membrane by an Inositol Polyphosphate 5-Phosphatase: Endogenous PtdIns(3)P Can Promote GLUT4 Translocation to the Plasma Membrane
【24h】

Phosphatidylinositol 3-Phosphate [PtdIns(3)P] Is Generated at the Plasma Membrane by an Inositol Polyphosphate 5-Phosphatase: Endogenous PtdIns(3)P Can Promote GLUT4 Translocation to the Plasma Membrane

机译:磷酸肌醇3-磷酸酯[PtdIns(3)P]是由肌醇多磷酸5-磷酸酶在血浆膜上产生的:内源性PtdIns(3)P可以促进GLUT4向血浆膜的转运

获取原文
           

摘要

Exogenous delivery of carrier-linked phosphatidylinositol 3-phosphate [PtdIns(3)P] to adipocytes promotes the trafficking, but not the insertion, of the glucose transporter GLUT4 into the plasma membrane. However, it is yet to be demonstrated if endogenous PtdIns(3)P regulates GLUT4 trafficking and, in addition, the metabolic pathways mediating plasma membrane PtdIns(3)P synthesis are uncharacterized. In unstimulated 3T3-L1 adipocytes, conditions under which PtdIns(3,4,5)P3 was not synthesized, ectopic expression of wild-type, but not catalytically inactive 72-kDa inositol polyphosphate 5-phosphatase (72-5ptase), generated PtdIns(3)P at the plasma membrane. Immunoprecipitated 72-5ptase from adipocytes hydrolyzed PtdIns(3,5)P2, forming PtdIns(3)P. Overexpression of the 72-5ptase was used to functionally dissect the role of endogenous PtdIns(3)P in GLUT4 translocation and/or plasma membrane insertion. In unstimulated adipocytes wild type, but not catalytically inactive, 72-5ptase, promoted GLUT4 translocation and insertion into the plasma membrane but not glucose uptake. Overexpression of FLAG-2xFYVE/Hrs, which binds and sequesters PtdIns(3)P, blocked 72-5ptase-induced GLUT4 translocation. Actin monomer binding, using latrunculin A treatment, also blocked 72-5ptase-stimulated GLUT4 translocation. 72-5ptase expression promoted GLUT4 trafficking via a Rab11-dependent pathway but not by Rab5-mediated endocytosis. Therefore, endogenous PtdIns(3)P at the plasma membrane promotes GLUT4 translocation.
机译:载体连接的磷脂酰肌醇3-磷酸[PtdIns(3)P]外源传递到脂肪细胞促进了葡萄糖转运蛋白GLUT4进入质膜的运输,但没有插入。但是,是否有证据表明内源性PtdIns(3)P调节GLUT4的运输,此外,介导质膜PtdIns(3)P合成的代谢途径尚未阐明。在未刺激的3T3-L1脂肪细胞中,在不合成PtdIns(3,4,5)P 3 的条件下,异位表达野生型但不催化失活的72-kDa肌醇多磷酸5-磷酸酶(72-5ptase),在质膜上生成PtdIns(3)P。脂肪细胞中的免疫沉淀72-5ptase水解PtdIns(3,5)P 2 ,形成PtdIns(3)P。 72-5ptase的过表达用于功能上解剖内源性PtdIns(3)P在GLUT4易位和/或质膜插入中的作用。在未刺激的脂肪细胞中,野生型但不是催化性失活的72-5ptase促进GLUT4易位并插入质膜,但不吸收葡萄糖。绑定和隔离PtdIns(3)P的FLAG-2xFYVE / Hrs的过表达阻止72-5ptase诱导的GLUT4易位。肌动蛋白单体的结合,使用latrunculin A处理,也阻断了72-5ptase刺激的GLUT4易位。 72-5蛋白酶表达通过Rab11依赖性途径促进GLUT4转运,但不通过Rab5介导的内吞作用促进。因此,质膜上的内源性PtdIns(3)P促进GLUT4易位。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号