Molecular Characterization of Hepatic Organic Anion Transporting Polypeptides

项目概要： 两种人类转运蛋白OATP 1B 1和OATP 1B 3在这一过程中起着关键作用 肝细胞对药物的摄取是肝胆药物处置的一个重要方面。 两种OATP都可以转运许多相同的常见药物，其功能可能会受到影响 通过其他药物或与其他蛋白质的相互作用，导致潜在危险的不良反应， 药物相互作用在以前的资助期间，我们已经证明，运输 OATP 1B 1或OATP 1B 3可被抑制或刺激，这取决于转运的底物。 然而，这种依赖于底物的摄取调节的分子机制和 蛋白质相互作用的调节机制尚不清楚。因为这两 相互作用可能导致药物不良反应，并影响OATP介导的药物 处置，其作用机制需要阐明。我们的长期研究目标是 详细了解OATP介导的转运机制，这是 了解、预测和预防OATP相关的不良药物相互作用。的 本申请的目的是阐明OATP 1B 1和OATP 1B 3 功能可以在人肝细胞中调节。我们的中心假设是OATP介导的 转运受相互作用的蛋白质调节。拟议研究的理由是， 了解OATP活性如何在相互作用蛋白质的存在下调节， 解释病理学观察结果、改善药物治疗和预防药物相互作用的信息 交互.此外，转运蛋白-蛋白质相互作用的表征将产生更多的 全面了解OATP转运机制。我们计划测试 有两个具体目标假设：1）识别和表征蛋白质-蛋白质机制 与OATP 1B 1和OATP 1B 3的相互作用;以及2）表征相互作用蛋白如何影响 OATP 1B介导的转运;完成这些特定目标将鉴定相互作用的蛋白质 与人类OATP 1B家族成员，阐明这种相互作用在多大程度上影响OATP- 介导的运输，从而药物处置，并阐明生理/病理生理方面 OATP 1B在人肝细胞中的表达。这一贡献意义重大，因为其结果 将扩大对OATP介导的 让我们了解潜在的相互作用，不仅在药物相互作用， 在蛋白质水平上也是如此。

PROJECT SUMMARY: The two human transporters OATP1B1 and OATP1B3 are crucial players in the process of drug uptake into hepatocytes which is an important aspect of hepatobiliary drug disposition. Both OATPs can transport many of the same common drugs and their function can be affected by other drugs or by interactions with other proteins, leading to potentially dangerous adverse drug interactions. In the previous grant periods, we have demonstrated that transport by OATP1B1 or OATP1B3 can be inhibited or stimulated depending on the transported substrate. However, the molecular mechanism of this substrate dependent modulation of uptake and the mechanism of modulation by protein interactions are not understood. Because both of these interactions can potentially lead to adverse drug effects and affect OATP-mediated drug disposition, their mechanism(s) of action need to be elucidated. Our long-term research goal is to understand in detail the mechanism of OATP-mediated transport as an essential prerequisite to understanding, predicting, and preventing OATP-related adverse drug-drug interactions. The objective of this application is to elucidate the mechanisms of how OATP1B1 and OATP1B3 function can be modulated in human hepatocytes. Our central hypothesis is that OATP-mediated transport is regulated by interacting proteins. The rationale for the proposed research is that understanding how OATP activity is regulated in the presence of interacting proteins may provide information to explain pathological observations, improve drug therapy, and prevent drug-drug interactions. Furthermore, the characterization of transporter-protein interactions will yield a more comprehensive understanding of the mechanisms of OATP transport. We plan to test the hypothesis with two specific aims: 1) Identify and characterize mechanisms of protein-protein interactions with OATP1B1 and OATP1B3; and 2) Characterize how the interacting proteins affect OATP1B-mediated transport; Completion of these specific aims will identify proteins that interact with human OATP1B family members, clarify to what extent such interactions affect OATP- mediated transport and thus drug disposition, and clarify physiological/pathophysiological aspects of OATP1B expression in human hepatocytes. This contribution is significant because its results will expand the fundamental understanding of the molecular mechanism of OATP-mediated transport and allow us to understand potential interactions not only at the drug-drug interaction level but also at the level of interacting proteins.