Molecular Characterization of Hepatic Organic Anion Transporting Polypeptides

项目总结： 两种人类转运蛋白OATP1B1和OATP1B3是这一过程中的关键角色 肝细胞对药物的摄取是肝胆药物处置的一个重要方面。 这两种OATP都可以运输许多相同的常见药物，它们的功能可能会受到影响 通过其他药物或通过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。在之前的赠款期间，我们已经通过以下方式展示了运输 根据运输底物的不同，OATP1B1或OATP1B3可被抑制或刺激。 然而，这种底物依赖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。因为这两件事 相互作用可能导致药物不良反应并影响OATP介导的药物 性格，他们的作用机制(S)需要阐明。我们的长期研究目标是 详细了解OATP介导的转运机制是 了解、预测和预防与OATP相关的药物-药物不良相互作用。这个 本应用的目的是阐明OATP1B1和OATP1B3的作用机制 人肝细胞的功能是可以调节的。我们的中心假设是OATP介导的 运输是由相互作用的蛋白质来调节的。建议进行这项研究的理由是 了解OATP活性是如何在相互作用蛋白存在的情况下调节的，可能会提供 解释病理观察、改进药物治疗和预防药物-药物的信息 互动。此外，转运蛋白-蛋白质相互作用的特征将产生更多 全面了解OATP的运输机制。我们计划测试一下 有两个特定目的的假说：1)识别和表征蛋白质-蛋白质的机制 与OATP1B1和OATP1B3的相互作用；以及2)相互作用的蛋白质如何影响 OATP1B介导的转运；完成这些特定的目的将识别相互作用的蛋白质 与人类OATP1B家族成员，阐明这种相互作用对OATP1B家族成员的影响程度- 介导转运，从而药物处置，并澄清生理/病理生理学方面 OATP1B在人肝细胞中的表达。这一贡献意义重大，因为它的结果是 将扩大对OATP介导的分子机制的基本认识 运输和让我们了解潜在的相互作用不仅仅是在药物与药物的相互作用 不仅在水平上，而且在相互作用蛋白质的水平上。

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.