CAREER: A Novel Twist in Nature; Proteins with a Pierced Lasso Topology

职业生涯：大自然的新奇转折；

• 批准号: 2145906
• 负责人: Ellinor Haglund
• 金额: $ 67.06万
• 依托单位: University of Hawaii
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-02-01 至 2027-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2145906&HistoricalAwards=false
• 关键词: CAREER; Novel; Twist; Nature; Proteins

With support from the Chemistry of Life Processes Program in the Chemistry Division and the Established Program to Stimulate Competitive Research (EPSCoR), Ellinor Haglund from the University of Hawaii is investigating a newly identified protein structure called the Pierced Lasso Topology (PLT). Proteins are sometimes called the “workhorses” in biology because they catalytically mediate the majority of chemical functions in a living cell. The breadth of these functions depends on the variety of three-dimensional shapes adopted by the chain of amino acids that make up proteins. The trace of a protein chain through space is called its topology. In a PLT, one end of the amino acid chain threads through a loop or lasso that is formed somewhere along the chain. This topology is similar to that of a simple overhand knot of a string or a rope. The chemical bond that forms the lasso can be made or broken, depending on the chemical environment of the system, and thus acts like an on/off switch for biological activity. Dr. Haglund will combine theoretical and biochemical studies with genetic experiments using fruit flies in order to investigate how PLTs can act as molecular switches to control biological activity through changes in the environment within cells. This project will be integrated with an outreach program to teach students and non-scientists how topologies seen in biology are connected with the topology of knots found in everyday life and in Polynesian culture. This research project aims to unravel functional insight for proteins with complex topologies, i.e., proteins with a pierced lasso topology (PLT). PLTs are threaded “knot-like” topologies wherein part of the chain pierces through a covalent loop. Interestingly, PLTs have been found to exist in 18% of all disulfide-containing proteins. Despite this large number, a connection between topology and biological function has not yet been established. As the first research group explicitly focusing on PLTs, the Haglund group will use biochemistry, cell biology, and biophysics tools to investigate functional consequences of disulfide chemistry in vivo and the possible role of disulfides as molecular switches to control biological activity. Molecular dynamics simulations, in vitro, and in vivo physiological assays using Drosophila melanogaster as a genetic model will be employed to examine the biological role of PLTs. This project sets out to reveal mechanistic details of how PLT proteins can fold and thread to reach their biologically active states. These studies will focus on three selected proteins (leptin, superoxide dismutase from Mycobacterium tuberculosis, and the chemokine CXCL5) that are involved in cell regulation, growth, and cell migration.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

在化学部生命过程化学计划和刺激竞争研究的既定计划（EPSCoR）的支持下，来自夏威夷大学的Ellinor Haglund正在研究一种新发现的蛋白质结构，称为刺穿套索拓扑结构（PLT）。蛋白质有时被称为生物学中的“主力”，因为它们催化介导活细胞中的大多数化学功能。这些功能的广度取决于组成蛋白质的氨基酸链所采用的各种三维形状。蛋白质链在空间中的轨迹称为它的拓扑。 在PLT中，氨基酸链的一端穿过在链的沿着某处形成的环或套索。这种拓扑结构类似于绳子或绳子的简单上手结。形成套索的化学键可以形成或断开，这取决于系统的化学环境，因此就像生物活性的开/关开关。Haglund博士将联合收割机理论和生物化学研究与果蝇遗传实验相结合，以研究PLT如何作为分子开关，通过细胞内环境的变化来控制生物活性。该项目将与一个外展计划相结合，教导学生和非科学家如何将生物学中的拓扑结构与日常生活和波利尼西亚文化中的结拓扑结构联系起来。该研究项目旨在揭示具有复杂拓扑结构的蛋白质的功能，即，具有刺穿套索拓扑结构（PLT）的蛋白质。PLT是螺纹“结样”拓扑结构，其中部分链穿过共价环。有趣的是，已发现PLT存在于所有含二硫化物蛋白质的18%中。尽管数量如此之大，拓扑结构和生物功能之间的联系尚未建立。作为第一个明确关注PLT的研究小组，Haglund小组将使用生物化学，细胞生物学和生物物理学工具来研究体内二硫化物化学的功能后果以及二硫化物作为分子开关控制生物活性的可能作用。分子动力学模拟，在体外，和在体内的生理检测使用果蝇作为遗传模型将被用来检查血小板的生物学作用。该项目旨在揭示PLT蛋白如何折叠和穿线以达到其生物活性状态的机制细节。这些研究将集中在三个选定的蛋白质（瘦素，结核分枝杆菌的超氧化物歧化酶，和趋化因子CXCL 5），参与细胞调节，生长和细胞迁移。这个奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

项目成果

A Small Contribution to a Large System: The Leptin Receptor Complex

对大系统的微小贡献：瘦素受体复合体

• DOI: 10.1021/acs.jpcb.3c01090
• 发表时间: 2023
• 期刊: The Journal of Physical Chemistry B
• 作者: Simien, Jennifer M.;Orellana, Grace E.;Phan, Hoa T.N.;Hu, Yao;Kurth, Emily A.;Ruf, Christine;Kricek, Franz;Wang, Qian;Smrcka, Alan V.;Haglund, Ellinor
• 通讯作者: Haglund, Ellinor

Topological Reaction Coordinate Captures the Folding Transition State Ensemble in a Pierced Lasso Protein

拓扑反应坐标捕获穿孔套索蛋白中的折叠过渡态整体

• DOI: 10.1021/acs.jpcb.3c06678
• 发表时间: 2024
• 期刊: The Journal of Physical Chemistry B
• 作者: Noel, Jeffrey K.;Haglund, Ellinor
• 通讯作者: Haglund, Ellinor

Exploring the folding landscape of leptin: Insights into threading pathways

探索瘦素的折叠景观：深入了解线程路径

• DOI: 10.1016/j.jsb.2023.108054
• 发表时间: 2024
• 期刊: Journal of Structural Biology
• 影响因子: 3
• 作者: da Silva, Fernando Bruno;Simien, Jennifer M.;Viegas, Rafael G.;Haglund, Ellinor;Leite, Vitor Barbanti
• 通讯作者: Leite, Vitor Barbanti

The Biological Implications of Threaded Protein Topologies

线程蛋白拓扑的生物学意义

• 发表时间: 2023
• 期刊: Chemical Engineering & Process Techniques
• 作者: Ellinor Haglund