Dunnett Louise, Das Sayan, Venditti Vincenzo, Prischi Filippo
Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot OX11 0QX, UK.
Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States.
bioRxiv. 2024 Dec 18:2024.12.17.628909. doi: 10.1101/2024.12.17.628909.
The human heterogeneous nuclear ribonucleoprotein (hnRNP) A1 is a prototypical RNA-binding protein essential in regulating a wide range of post-transcriptional events in cells. As a multifunctional protein with a key role in RNA metabolism, deregulation of its functions has been linked to neurodegenerative diseases, tumour aggressiveness and chemoresistance, which has fuelled efforts to develop novel therapeutics that modulates its RNA binding activities. Here, using a combination of Molecular Dynamics (MD) simulations and graph neural network pockets predictions, we showed that hnRNPA1 N-terminal RNA binding domain (UP1) contains several cryptic pockets capable of binding small molecules. To identify chemical entities for development of potent drug candidates and experimentally validate identified druggable hotspots, we carried out a large fragment screening on UP1 protein crystals. Our screen identified 36 hits which extensively samples UP1 functional regions involved in RNA recognition and binding, as well as mapping hotspots onto novel protein interaction surfaces. We observed a wide range of ligand-induced conformational variation, by stabilisation of dynamic protein regions. Our high-resolution structures, the first of an hnRNP in complex with a fragment or small molecule, provides rapid routes for the rational development of a range of different inhibitors and chemical tools for studying molecular mechanisms of hnRNPA1 mediated splicing regulation.
人类异质性核核糖核蛋白(hnRNP)A1是一种典型的RNA结合蛋白,对调节细胞中广泛的转录后事件至关重要。作为一种在RNA代谢中起关键作用的多功能蛋白,其功能失调与神经退行性疾病、肿瘤侵袭性和化疗耐药性有关,这推动了开发调节其RNA结合活性的新型疗法的努力。在这里,我们结合分子动力学(MD)模拟和图神经网络口袋预测,表明hnRNPA1 N端RNA结合结构域(UP1)包含几个能够结合小分子的隐蔽口袋。为了识别用于开发有效药物候选物的化学实体并通过实验验证已识别的可成药热点,我们对UP1蛋白晶体进行了大规模片段筛选。我们的筛选确定了36个命中物,这些命中物广泛采样了参与RNA识别和结合的UP1功能区域,并将热点映射到新的蛋白质相互作用表面。我们通过稳定动态蛋白质区域观察到了广泛的配体诱导的构象变化。我们的高分辨率结构是hnRNP与片段或小分子复合物的首个结构,为合理开发一系列不同的抑制剂和化学工具以研究hnRNPA1介导的剪接调控的分子机制提供了快速途径。