Meech R, Mackenzie P I
Department of Clinical Pharmacology, Flinders University of South Australia, Bedford Park, SA, 5042, Australia.
Arch Biochem Biophys. 1998 Aug 1;356(1):77-85. doi: 10.1006/abbi.1998.0750.
The UDP glucuronosyltransferases (UGT)2 are a family of enzymes which detoxify small hydrophobic compounds in mammalian cells. It is believed that UGTs are type I endoplasmic reticulum (ER) resident membrane proteins with a single membrane spanning domain near the carboxyl-terminus. The determinants of endoplasmic reticulum subcellular localization and membrane association for the UDP glucuronosyltransferase, UGT2B1, were examined. The construction and analysis of truncated and chimeric forms of UGT2B1 demonstrated that the protein contains regions of membrane interaction in the amino-terminal half of the lumenal domain in addition to the carboxyl-terminal transmembrane domain. UGT2B1 also remained resident in the ER in the absence of the cytosolic tail and transmembrane domain. Construction and analysis of an active, truncated form of UGT2B1 indicated that the cytosolically located dilysine motif, which is a putative ER membrane targeting signal, may be redundant for residency of UGT in the ER.
UDP葡糖醛酸基转移酶（UGT）2是一类在哺乳动物细胞中使小的疏水性化合物解毒的酶。据信，UGT是I型内质网（ER）驻留膜蛋白，在羧基末端附近有一个单跨膜结构域。对UDP葡糖醛酸基转移酶UGT2B1的内质网亚细胞定位和膜结合的决定因素进行了研究。UGT2B1截短形式和嵌合形式的构建与分析表明，除了羧基末端跨膜结构域外，该蛋白在腔结构域氨基末端的一半还包含膜相互作用区域。在没有胞质尾和跨膜结构域的情况下，UGT2B1也仍驻留在内质网中。UGT2B1活性截短形式的构建与分析表明，作为一种假定的内质网膜靶向信号的位于胞质中的双赖氨酸基序，对于UGT在内质网中的驻留可能是多余的。
