N-glycosylation of ABC transporters is associated with functional activity in sandwich-cultured rat hepatocytes
N-glycosylation of ABC transporters is associated with functional activity in sandwich-cultured rat hepatocytes
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DOI：
10.1016/j.ejps.2010.06.005
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发表时间：
2010-10-09
影响因子：
4.6
通讯作者：
Moenning, Ursula
中科院分区：
文献类型：
--
作者：
Draheim, Viola;Reichel, Andreas;Moenning, Ursula
肝胆小管外流转运蛋白在清除内源性和外源性生物物质中起着关键作用。正确的膜定位和转运系统的协调作用对于药物从血液到胆汁的载体转运至关重要。虽然基底局部摄取转运体负责物质从血液向内转运到肝细胞，但顶部表达的ATP依赖的转运蛋白，如P-糖蛋白(P-gp)、多药耐药相关蛋白(MRP2)和乳腺癌耐药蛋白(BCRP)介导了物质向外流出到胆小管。利用夹心培养的大鼠肝细胞，我们研究了P-gp、mrp2和BCRP转运蛋白的表达和成熟，以及它们在几天内的转运功能。肝细胞的再分化只发生在三明治结构中，包括新星合成和随后所有三种转运蛋白的翻译后N-糖基化。只有完全N-糖基化的转运蛋白亚型与功能活性有关，通过将特定的荧光底物排泄到小管网络中而可见。然而，N-糖基化如何影响所研究的ABC转运蛋白的功能活性仍有待确定。(C)2010爱思唯尔B.V.保留所有权利。
Hepatobiliary elimination via canalicular efflux transport proteins plays a key role in the clearance of endo- and xenobiotics. Correct membrane localization and coordinated action of the transport systems are essential for vectorial transport of drugs from blood into the bile. While basolaterally localized uptake transporters are responsible for the inward transport of substances from the blood into the hepatocyte, apically expressed ATP-dependent transport proteins such as P-glycoprotein (P-gp), multidrug resistance-associated protein (Mrp2) and breast cancer resistance protein (Bcrp) mediate the outward efflux into the bile canaliculus. Using sandwich-cultured rat hepatocytes we have characterized the expression and maturation of P-gp, Mrp2 and Bcrp transport proteins as well as their transport function over several days. The re-differentiation of the hepatocytes, which only occurs in sandwich configuration involves de nova synthesis and subsequent posttranslational N-glycosylation of all three transport proteins. Only fully N-glycosylated isoforms of the transporters were associated with functional activity as visualized by excretion of specific fluorescent substrates into the canalicular network. However, in what way N-glycosylation affects the functional activity of the ABC transporters investigated remains to be determined. (C) 2010 Elsevier B.V. All rights reserved.