Acute effectors of GLUT1 glucose transporter subcellular targeting in CIT3 mouse mammary epithelial cells
Acute effectors of GLUT1 glucose transporter subcellular targeting in CIT3 mouse mammary epithelial cells
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DOI：
10.1203/pdr.0b013e31815b440b
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发表时间：
2008-01-01
影响因子：
3.6
通讯作者：
Mond, Yehudit
中科院分区：
文献类型：
--
作者：
Riskin, Arieh;Nannegari, Veena H.;Mond, Yehudit
乳原激素引起细胞内葡萄糖转运蛋白1 （GLUT1）的靶向，将葡萄糖转运到乳腺中的乳糖合成部位。我们的目的是研究在CIT3小鼠乳腺上皮细胞中参与GLUT1靶向和再循环的细胞内运输机制。GLUT1和增强型绿色荧光蛋白（EGFP）融合蛋白在生长培养基（GM）和分泌培养基（SM）中表达。研究了肌肉和脂肪细胞中高尔基体和相关亚细胞区室以及GLUT1和GLUT4靶向作用的药物。Wortmannin和staurosporine对GLUT1内化的影响不具有特异性，支持CIT3细胞胞内池和细胞表面之间的基本组成性GLUT1膜循环途径，该途径在GM中将大多数GLUT1靶向到质膜上。在SM中暴露于泌乳素后，GLUT1特异性靶向到细胞内的brefeldin a敏感室。巴菲霉素A1抑制内体酸化破坏了这种催乳素诱导的GLUT1细胞内运输，并伴有GLUT1- egfp信号的中心合并，表明它是通过内体途径进行的。这种机制通过在几分钟到几小时内改变GLUT1的靶向性，提供了另一种水平的乳糖合成调节。
Lactogenic hormones cause intracellular targeting of glucose transporter 1 (GLUT1) for transport of glucose to the site of lactose synthesis in mammary glands. Our aim was to study the intracellular trafficking mechanisms involved in GLUT1 targeting and recycling in CIT3 mouse mammary epithelial cells. Fusion proteins of GLUT1 and enhanced green fluorescent protein (EGFP) were expressed in CIT3 cells maintained in growth medium (GM), or exposed to secretion medium (SM), containing prolactin. Agents acting on Golgi and related subcellular compartments and on GLUT1 and GLUT4 targeting in muscle and fat cells were studied. Wortmannin and staurosporine effects on internalization of GLUT1 were not specific, supporting a basal constitutive GLUT1 membrane-recycling pathway between an intracellular pool and the cell surface in CIT3 cells, which targets most GLUT1 to the plasma membrane in GM. Upon exposure to prolactin in SM, GLUT1 was specifically targeted intracellularly to a brefeldin A-sensitive compartment. Arrest of endosomal acidification by bafilomycin A1 disrupted this prolactin-induced GLUT1 intracellular trafficking with central coalescence of GLUT1-EGFP signal, suggesting that it is via endosomal pathways. This machinery offers another level of regulation of lactose synthesis by altering GLUT1 targeting within minutes to hours.