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一、资助家长奖摘要R01 GM140584 这项提议试图了解位于细胞膜中的蛋白质是如何作为守门人工作的 有选择地允许化合物进入或离开细胞。这样的看门人被称为三磷酸腺苷结合盒(ABC) 转运体，因为它们使用ATP(三磷酸腺苷)水解的能量来运输化合物 穿过细胞膜。细菌ABC进口体对于生物体的生存是必不可少的，控制着 吸收从细菌环境中清除的营养物质。对运输速度的控制防止了过度- 一种营养物质的积累，这种物质在低浓度时有益，但在高浓度时具有潜在的毒性。 而ABC蛋白的一个子集包含一个额外的“辅助”结构域，它可以调节对 通过关闭转运蛋白来合成化合物，目前尚不清楚为什么某些转运蛋白含有这些结构域 其他人则不这么认为。然而，我们确实理解，当一种特定的化合物时，某些转运体被“关闭” 或蛋白质结合到这个辅助结构域。其他辅助域通过“感知” 微环境和相应的反应。为了破译这种调节机制，PI的实验室 将生化和生物物理实验与结构生物学相结合，以了解这些附件是如何 结构域在运输调节中发挥作用，它限制或允许营养物质进入细胞。这项研究 该计划将定义控制营养吸收的分子机制，并允许研究人员了解 生物体内多种运输系统如何协同工作以维持细胞存活。我们将测试我们的 假设通过感知辅助蛋白调节转运蛋白的激活。拟议的研究将 破译模型系统中复杂的调节电路有三个目的：(1)了解PepT SBP如何 在微环境中选择不同的底物(即营养物质、辅因子和多肽)；(2)确定 核心转运体的组装如何决定传输的选择性和效率(3)揭示了PepT如何 转运蛋白通过激活一个新的调控结构域来调节底物进入细胞。 这项研究计划致力于弥合对运输基本原理的理解上的关键差距 这一机制存在于所有细菌中。这些结果将深入了解监管领域是如何调节交通的 在所有生物体中，对细胞存活至关重要。 资助家长奖没有任何变化

I. SUMMARY OF THE FUNDED PARENT AWARD R01 GM140584 This proposal seeks to understand how proteins located in the cell membrane work as gatekeepers to selectively allow compounds into or out of the cell. Such gatekeepers are known as ATP-binding cassette (ABC) transporters because they use the energy of ATP (adenosine triphosphate) hydrolysis to transport compounds across the cell membrane. Bacterial ABC importers are essential for organism survival, controlling the rate of uptake for nutrients scavenged from the bacterium's environment. Control of the rate of transport precludes over- accumulation of a nutrient that is beneficial at low concentrations but is potentially toxic at high concentrations. While a subset of ABC proteins contain an additional “accessory” domain that can regulate the uptake of compounds by shutting off the transporter, it is unclear why certain transporters contain these domains while others do not. However, we do understand that certain transporters are “turned off” when a specific compound or protein binds to this accessory domain. Other accessory domains regulate by “sensing” changes in the microenvironment and reacting accordingly. To decipher this mechanism of regulation, the PI's laboratory combines biochemical and biophysical experiments with structural biology to understand how these accessory domains play a role in transport regulation, which in restricts or allows nutrients to enter the cell. This research program will define the molecular mechanism that controls nutrient uptake and allow researchers to understand how multiple transport systems work in concert within an organism to maintain cell survival. We will test our hypothesis that regulation of transporter activation via a sensing accessory protein. The proposed research will decipher the complex circuitry of regulation in a model system in three Aims to: (1) understand how PepT SBPs select for different substrates within the microenvironment (i.e., nutrients, cofactors, and peptides); (2) determine how the assembly of the core transporter dictates transport selectivity and efficiency (3) reveal how PepT transporters regulate the import of substrates into the cell through the activation of a novel regulatory domain. This research program has set out to close critical gaps in the understanding of the fundamentals of the transport mechanism present in all bacteria. The results will yield insights into how regulatory domains modulate transport across all organisms, crucial for cell viability. There are no changes to the funded parent award