RUI: The role of protein acetylation in stress responses and in setting tolerance limits in differently adapted mussels (genus Mytilus): a comparative proteomics approach

本研究的重点是蛋白质修饰在海洋生物对各种环境胁迫的反应中的作用。这些反应的特征可能决定了对这些压力源的耐受性限制，并且在很大程度上由控制许多细胞过程的蛋白质催化剂控制。这项研究将确定一种特定的蛋白质修饰是否参与了海洋贻贝对环境胁迫的反应，并评估其在设定对热应激、氧气限制和海洋酸化的耐受极限方面的作用。蛋白质丰度的变化是细胞如何保护自己免受结构损伤和重新调整细胞过程以在变化的环境中维持细胞功能的关键指标。蛋白质合成和降解是昂贵的过程；因此，其他控制蛋白质功能的方法也随之进化。通过在蛋白质翻译后添加一些化学基团（即翻译后修饰或“PTMs”），蛋白质功能可以得到很大的改变。最近，研究表明，广泛的细胞功能是由被称为乙酰化酶和去乙酰化酶的酶调节的，它们在蛋白质上或从蛋白质上添加或去除乙酰基。Sirtuins是一类去乙酰化酶，现在已知它影响许多细胞过程，这些细胞过程将细胞周期与能量代谢和氧化应激联系起来。首席研究员使用两种独立的蛋白质组学方法进行的初步观察表明，热应激改变了sirtuins的丰富程度，并且在两种蓝贻贝同属（Mytilus）的鳃组织中，18-55%的蛋白质在热应激期间受到sirtuins诱导的去乙酰化的影响，这两种蓝贻贝的热耐受性不同，这是迄今为止未知的任何PTM的活性范围。本研究将评估（去）乙酰化在细胞对热应激、氧气限制和海洋酸化的反应中的全局作用，评估（去）乙酰化在设定耐受极限中的重要性，并确定各种去乙酰化酶对蛋白质乙酰化模式的贡献。这项研究将有助于确立（去）乙酰化作为海洋生物对环境应激反应中蛋白质功能的关键调节因子的普遍重要性。本科生和研究生以及访问学者将接受蛋白质组学技术的培训，包括质谱法。首席研究员与许多同事合作，围绕环境蛋白质组学建立了一个社区，在最近的一次会议上组织了一个关于该主题的研讨会，并正在开发一个为期两周的蛋白质组学技术培训课程。他在一些关于有机体适应快速变化的环境条件的公开讲座中传播他的研究。他的工作为物种、分布模式的机械决定因素提供了见解，并为预测气候变化的影响做出了贡献。

This study focuses on the role of protein modification in responses of marine organisms to a variety of environmental stressors. The characteristics of such responses may determine tolerance limits to these stressors, and are largely controlled by protein catalysts that govern many cellular processes. This research will determine whether a specific protein modification is involved in responses to environmental stress by marine mussels, and assess its role in setting tolerance limits to heat stress, oxygen limitation and ocean acidification. A change in protein abundance is a key indicator of how cells protect themselves from structural damage and readjust cellular processes to maintain cellular function in a changing environment. Protein synthesis and degradation are costly processes; therefore other means of controlling protein function have evolved. Protein function can be greatly modified by the addition of a number of chemical groups after protein translation (i.e., post-translational modifications or "PTMs"). Recently, it has been shown that a broad range of cellular functions are regulated by enzymes called acetylases and deacetylases, which add or remove an acetyl group to or from proteins. Sirtuins, one class of deacetylases, are now known to affect many cellular processes that link the cell cycle to energy metabolism and oxidative stress. Preliminary observations by the principal investigator using two independent proteomic methods demonstrated that heat stress changes the abundance of sirtuins, and that 18-55% of proteins are affected by sirtuin-induced deacetylation during heat stress in gill tissue of two blue mussel congeners (Mytilus) that differ in thermal tolerance, a heretofore unknown scope of activity for any PTM. This study will assess the global role of (de-)acetylation during the cellular response to heat stress, oxygen limitation and ocean acidification, evaluate the importance of (de-)acetylation in setting tolerance limits, and establish the contribution of various deacetylases to patterns of protein acetylation. This research will help establish the general importance of (de-)acetylation as a key regulator of protein function in response to environmental stress in marine organisms. Undergraduate and graduate students, as well as visiting scholars will be trained in proteomic techniques, including mass spectrometry. The principal investigator has collaborated with a number of colleagues to build a community around environmental proteomics, has organized a symposium on the topic at a recent conference, and is developing a two-week training course on proteomic techniques. He is disseminating his research in a number of public lectures on adaptation of organisms to rapidly changing environmental conditions. His work is providing insights into mechanistic determinants of species, distribution patterns, and is contributing to the goal of predicting the effects of climate change.