Extensive Protein-Protein Interactions Involving UDP-glucuronosyltransferase (UGT) 2B7 in Human Liver Microsomes
Extensive Protein-Protein Interactions Involving UDP-glucuronosyltransferase (UGT) 2B7 in Human Liver Microsomes
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DOI：
10.2133/dmpk.dmpk-13-rg-096
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发表时间：
2014-06-25
影响因子：
2.1
通讯作者：
Itoh, Tomoo
中科院分区：
文献类型：
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作者：
Fujiwara, Ryoichi;Itoh, Tomoo
UDP-葡萄糖醛酸转移酶（UGT）2B 7是一种膜蛋白，催化内源性和外源性底物的葡萄糖醛酸化。由于UGT在内质网（ER）中表达，因此其底物和代谢物需要通过ER膜转运。然而，深入了解UGT的底物/代谢物通过ER膜的运输机制尚未阐明。代谢体是由多种代谢相关蛋白组成的代谢功能单位。UGT可能形成代谢体，以促进其底物和/或代谢物通过ER膜的转运。因此，在本研究中，通过免疫沉淀物的鸟枪分析确定了涉及UGT 2B 7的广泛的蛋白质-蛋白质相互作用。我们的鸟枪分析显示，92蛋白与抗UGT 2B 7抗体在人肝微粒体中的免疫沉淀。我们进一步确定了92种蛋白质中的42种蛋白质与抗UGT 2B 7抗体特异性免疫沉淀。除UGT 2B 7外，其他微粒体酶（如UGT 1A、CYP 3A 4、CYP 1A 2和单胺氧化酶）也包括在抗UGT 2B 7抗体免疫沉淀的蛋白质列表中，表明这些蛋白质可能形成代谢体以调节其在肝脏中的功能。需要进一步的分析来阐明这些蛋白质在人UGT酶活性中的作用。
UDP-glucuronosyltransferase (UGT) 2B7 is a membrane protein that catalyzes glucuronidation of endogenous and exogenous substrates. Because UGTs are expressed in the endoplasmic reticulum (ER), their substrates and metabolites need to be transported through the ER membrane. However, insight into the mechanism underlying the transport of substrates/metabolites of UGTs through the ER membrane has not been elucidated. Metabolosome is a functional unit of metabolism consisting of multiple metabolismrelated proteins. UGTs might form a metabolosome to facilitate the transport of their substrates and/or metabolites through the ER membrane. In the present study, therefore, extensive protein-protein interactions involving UGT2B7 were determined by a shotgun analysis of immunoprecipitate. Our shotgun analysis revealed that 92 proteins were immunoprecipitated with anti-UGT2B7 antibody in human liver microsomes. We further determined that 42 proteins out of the 92 proteins were specifically immunoprecipitated with the anti-UGT2B7 antibody. In addition to UGT2B7, other microsomal enzymes such as UGT1A, CYP3A4, CYP1A2, and a monoamine oxidase, were included in the list of proteins immunoprecipitated with the anti-UGT2B7 antibody, suggesting that these proteins might form a metabolosome to regulate their functions in the liver. Further analyses are needed to elucidate the roles of those proteins in the enzymatic activity of human UGTs.