Regulation Of Protein Metabolism By Cellular Signaling Pathways In Stressed Fish

动物通过合成蛋白质来产生软组织，并在蛋白质生长的过程中保留一定比例；其余的被降解，氨基酸被循环利用。这些相互关联的蛋白质合成、生长和降解过程统称为蛋白质代谢。在鱼类中，蛋白质代谢对各种各样的生物和非生物因素高度敏感，包括温度、污染、食物可获得性，可能还包括个人的社会地位。蛋白质代谢是高度调节的，在细胞水平上，这种调节涉及信号转导途径。在过去的十年里，我们对信号转导通路在控制蛋白质代谢中的作用的了解已经取得了很大的进展，但仍有许多有待了解的地方，特别是在非哺乳动物动物中。我的研究计划的长期目标是：1)确定参与蛋白质新陈代谢控制的细胞机制的特征；2)使用这些细胞机制来提取关于饲养或从野外收集的动物的生理状态的信息。*在未来五年，我将应用多学科方法，以建立社会等级后观察到的从属鱼类的生长抑制为模型，研究蛋白质新陈代谢的控制。这种生长抑制主要是由于食物消耗量的大幅减少造成的，但压力荷尔蒙皮质醇也在其中起到了作用。拟议研究活动的短期目标是1)表征饥饿期间蛋白质代谢调节的细胞机制，2)表征急性和长期升高的皮质醇对蛋白质代谢的影响，3)评估饥饿和长期升高的皮质醇对从属鱼类生长抑制的各自贡献。该研究计划涉及与当前工业(水产养殖)和环境问题高度相关的鱼类生理学的一个重要方面。

Animals produce soft tissues by synthesizing proteins and retaining a proportion as protein growth; the remainder being degraded and the amino acids recycled. These interrelated processes of protein synthesis, protein growth and protein degradation are collectively called protein metabolism. In fish, protein metabolism is highly sensitive to a wide variety of biotic and abiotic factors including temperature, pollution, food availability and probably to the individual's social status. Protein metabolism is highly regulated and, at the cellular level, this regulation involves the signal transduction pathways. In the last decade, our understanding of the roles of the signal transduction pathways in the control of protein metabolism has greatly progressed however much remains to be understood, especially in non-mammalian animals. The long-term goals of my research program are; 1) to characterize the cellular mechanisms involved in the control of protein metabolism and 2) to use these cellular mechanisms to extract information on the physiological status of animals that are either farmed or collected from the wild. ** **In the next five years, I will apply a multidisciplinary approach to study the control of protein metabolism using the growth depression observed in subordinate fish following the establishment of social hierarchy as a model. This growth depression is primarily caused by a dramatic reduction of food consumption however the stress hormone cortisol also plays a role in it. The short term objectives of the proposed research activities are 1) To characterize the cellular mechanisms involved in the adjustments of protein metabolism during starvation, 2) To characterize the effects of acutely and chronically elevated cortisol on protein metabolism, 3) To evaluate the respective contribution of starvation and chronically elevated cortisol on growth depression in subordinate fish. This research program addresses an important aspect of fish physiology that is highly relevant to current industrial (aquaculture) and environmental issues.**