Investigating the molecular mechanisms regulating protein ubiquitylation in skeletal muscle following physical activity

体育活动是一种公认的促进全身健康的生理刺激。在进行体力活动时，由于骨骼肌组织在运动和代谢中的作用，身体高度依赖骨骼肌组织。因此，缺乏身体活动会损害骨骼肌的质量和功能，导致代谢疾病和衰老。蛋白质泛素化在控制骨骼肌质量和功能中的作用已被广泛接受。然而，运动后蛋白质泛素化的反应研究很少，特别是涉及的分子机制。为了解决这一知识差距，我的博士项目旨在研究运动后骨骼肌中蛋白质泛素化是如何调节的。为此，该项目将重点关注E3连接酶和去泛素化酶在急性运动后的反应。E3连接酶使泛素转移到蛋白质底物上，而去泛素化酶（DUBs）逆转这一反应并从底物上去除泛素。因此，这些酶是调节蛋白质泛素化的关键分子机制。首先，我们的目标是确定哪些E3连接酶和dub会因运动而改变，为我们提供一个候选酶的列表。接下来，我们将通过质谱法检查它们的底物，以更好地了解所涉及的信号通路。最后，我们将采用一种敏感的蛋白质组学方法来研究人类骨骼肌中运动调节的泛素组。总之，这个项目将提高我们对运动调节蛋白泛素化的理解，为骨骼肌生物学揭示一个新的层面。

Physical activity is a well-established physiological stimulus for improving whole-body health. When performing physical activity, the body is highly dependent on skeletal muscle tissue due to its role in both locomotion and metabolism. As a result, physical inactivity impairs skeletal muscle mass and function, resulting in metabolic diseases and ageing. The role of protein ubiquitylation for controlling skeletal muscle mass and function has become widely accepted. However, the response of protein ubiquitylation following exercise is poorly researched, especially in relation to the molecular mechanisms involved. To address this knowledge gap, my PhD project aims to investigate how protein ubiquitylation is regulated in skeletal muscle following physical activity. To do this, this project will be focusing on the response of both E3 ligases and de-ubiquitylating enzymes following acute exercise. E3 ligases enable the transfer of ubiquitin onto a protein substrate, whereas de-ubiquitylases (DUBs) reverse this reaction and remove the ubiquitin from the substrate. Therefore, these enzymes are the key molecular mechanisms regulating protein ubiquitylation. Firstly, we aim to determine which E3 ligases and DUBs are altered in response to exercise, providing us with a list of candidate enzymes to focus on. Next, we will examine their substrates through mass-spectrometry to better understand the signalling pathways involved. Finally, we will employ a sensitive proteomic approach to investigate the exercise-regulated ubiquitylome in human skeletal muscle. Together, this project will improve our understanding of exercise-regulated protein ubiquitylation, exposing a new layer to skeletal muscle biology.