NSF Postdoctoral Fellowship in Biology: Illuminating mechanisms of essential asparagine-linked glycosylation enzymes

该行动资助了美国国家科学基金会2023财年生物学博士后研究奖学金，扩大生物学中代表性不足群体的参与。该奖学金支持研究员的研究和培训计划，该计划将增加在生物学中代表性不足的群体的参与。氨基酸是生命的基本组成部分之一。所有的细胞都使用氨基酸来制造更大、更复杂的蛋白质结构，其中一些需要额外的改变来确保正常的功能。在某些蛋白质中，这种变化包括复杂的糖分子附着在特定的氨基酸上；这个过程被称为糖基化。一旦连接，这些糖在控制蛋白质的功能以及蛋白质如何与其他分子相互作用方面发挥作用。没有糖基化，蛋白质的功能就会不正常，破坏基本的生物功能。在人类中，这可能导致许多先天性疾病和癌症。尽管它起着至关重要的作用，但人们对糖基化中使用的复合糖是如何产生的知之甚少。因此，这项研究旨在研究制造这些糖的酶；这项工作通过了解酶的分子结构来探索酶的功能。因为糖基化对所有生命都很重要，了解这些酶将为指导未来生物技术的应用创造新的见解，包括设计针对先天性糖基化疾病和癌症的新疗法。此外，这项工作将促进该研究员直接培训和指导不同的受训者开展自己的科学事业的能力。这项工作将通过定义磷酸化转移酶和糖基转移酶的广泛催化机制，并制定适用于所有生命领域的NLG的基本原则，丰富天冬酰胺连接糖基化（NLG）的基础知识。利用重组蛋白在人细胞中的表达、结构生物学、生物信息学和生物化学，本工作将全面表征人磷酸转移酶DPATG1及其伙伴糖基转移酶Alg13和Alg14。这项工作还将研究其他必需的NLG糖基转移酶之间的新相互作用。为了实现这一目标，研究员将通过冷冻电镜（cryo-EM）确定人类DPAGT1与新型抑制剂复合物的结构。然后，研究员将对DPAGT1/Alg13/Alg14复合物进行结构表征。最后，该研究员将利用AlphaFold探测未表征的异寡聚复合物，并从NLG途径中定义整体膜磷酸转移酶和糖基转移酶的普遍机制。该研究员将参加低温电子显微镜培训讲习班和特定领域的会议。最后，该研究员将在现有基础设施的基础上，为来自历史上被边缘化背景的学生和博士后创建一个全校范围的网络，旨在建立社区、专业发展，并将受训者与现有资源联系起来。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2023, Broadening Participation of Groups Underrepresented in Biology. The Fellowship supports a research and training plan for the Fellow that will increase the participation of groups underrepresented in biology. Amino acids are one of the essential building blocks of life. All cells use amino acids to create larger, more complex structures called proteins, with several requiring additional changes to ensure proper function. In some proteins, one such change involves the attachment of complex sugar molecules to specific amino acids; this process is called glycosylation. Once attached, these sugars play roles in controlling how proteins function and how proteins interact with other molecules. Without glycosylation, proteins would function improperly, disrupting essential biological functions. In humans, this can lead to numerous congenital disorders and cancers. Despite its critical role, little is understood about how the complex sugars used in glycosylation are generated. Thus, this research seeks to investigate the enzymes that make these sugars; this work explores enzyme function by understanding their molecular structures. Because glycosylation is important for all life, understanding these enzymes will create new insights that guide future applications in biotechnology, including designing new therapeutics that target congenital disorders of glycosylation and cancers. Moreover, this work will facilitate the fellow’s ability to directly train and mentor diverse trainees navigating their own scientific careers. This work will enrich foundational knowledge of asparagine-linked glycosylation (NLG) by defining broad catalytic mechanisms of phosphotransferases and glycosyltransferases, and formulating underlying principles applicable to NLG in all domains of life. Using recombinant protein expression in human cells, structural biology, bioinformatics, and biochemistry, this work will fully characterize the human phosphotransferase, DPATG1, and its partner glycosyltransferases Alg13 and Alg14. This work will also investigate novel interactions between other essential NLG glycosyltransferases. To achieve this, the fellow will determine the structure of human DPAGT1 in complex with novel inhibitors by cryo-EM. Then, the fellow will structurally characterize the DPAGT1/Alg13/Alg14 complex. Lastly, the fellow will leverage AlphaFold to probe uncharacterized heterooligomeric complexes and define universal mechanisms of integral membrane phosphotransferases and glycosyltransferases from the NLG pathway. The fellow will attend cryo-EM training workshops and field-specific conferences. Lastly, the fellow will build upon existing infrastructure to create a campus-wide network for students and postdocs from historically marginalized backgrounds that seeks to build community, professional development, and connect trainees with existing resources.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.