RUI: Evolutionary Origins of BACE1 and Amyloid-Beta

这项工作研究了两种蛋白质的进化，这两种蛋白质广泛分布于后生动物中，也是人类阿尔茨海默病(AD)的基础--β-分泌酶(BACE1)和淀粉样β蛋白(A-β)序列。主要目标是了解随着时间的推移，蛋白质分子何时以及如何进化出新的功能。这项工作的更广泛成果包括为代表不足的少数群体和第一代本科生扩大获得STEM研究的机会，并通过一个高中教学模块和一篇科普文章向更广泛的社区推广。基因复制被认为是新蛋白质功能进化的主要促进因素。BACE1是从动物起源后的一次基因复制事件进化而来的。在后来的一个未知的时间点，APP基因复制进化出了一个新的BACE1底物基序(A-β)。该项目追溯了这些分子的起源和相互作用的功能进化历史，并尽可能精确地解决了BACE1和APP/A-beta进化的问题。这项研究有两个具体目标：(1)通过基于细胞培养的功能测试和ELISA，确定BACE1活性的功能来源，调查哪些物种保留BACE1酶活性，以及(2)确定APPβ裂解位点的功能来源，以确定哪些分类群保留真正的BACE1底物，使用基于细胞培养的功能测试和质谱仪。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This work examines the evolution of two proteins that are widely distributed in metazoan animals and underlie Alzheimer's disease (AD) in humans - the beta-secretase enzyme (BACE1) and the amyloid beta (A-beta) sequence. The main goal is to understand when and how protein molecules evolve new functions over time. Broader outcomes of this work include expanded access to STEM research for underrepresented minorities and first generation undergraduate students, and outreach to the broader community via a high school teaching module and a popular science article. Gene duplications are believed to be major facilitators of the evolution of novel protein function. BACE1 evolved from a gene duplication event just after the origin of animals. At a later but as yet unknown point in time, an APP gene duplicate evolved a novel BACE1 substrate motif (A-beta). This project traces back the functional evolutionary history of the origin and interaction of these molecules and resolves, to the most precise degree possible, when BACE1 and APP/A-beta evolved. Two specific aims make up this research: (1) determining the functional origin of BACE1 activity, via a cell culture-based functional test and ELISA, to investigate which species retain BACE1 enzymatic activity, and (2) determining the functional origin of the APP beta cleavage site to determine which taxa retain bona fide BACE1 substrates, using a cell culture-based functional test and mass spectrometry.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.