Abstract：
A decrease in environmental temperature represents a challenge to the cardiovascular system of ectotherms. To gain insight into the cellular changes that occur during cold exposure and cold acclimation we characterized the cardiac phosphoproteome and proteome of zebrafish following 24 h or one week exposure to 20 oC from 27 oC; or at multiple points during six weeks of acclimation to 20 oC from 27 oC. Our results indicate that cold exposure causes an increase in mitogen-activated protein kinase signaling, the activation of stretch sensitive pathways, cellular remodeling via ubiquitin-dependent pathways, and changes to the phosphorylation state of proteins that regulate myofilament structure and function including desmin and troponin T. Cold acclimation (2-6 weeks) led to a decrease in multiple components of the electron transport chain through time, but an increase in proteins for lipid transport, lipid metabolism, the incorporation of polyunsaturated fatty acids into membranes and protein turnover. For example, there was an increase in the levels of apolipoprotein C, prostaglandin reductase-3, and surfeit locus protein 4, involved in lipid transport, lipid metabolism, and lipid membrane remodeling. Gill opercular movements suggests that oxygen utilization during cold acclimation is reduced. Neither the amount of food consumed relative to body mass nor body condition were affected by acclimation. These results suggest that while oxygen uptake was reduced, energy homeostasis was maintained. This study highlights that the response of zebrafish to a decrease in temperature is dynamic through time and that investment in the proteomic response increases with the duration of exposure.
摘要：
环境温度的降低代表了对心血管系统的挑战。为了深入了解冷暴露和冷适应过程中发生的细胞变化，我们对斑马鱼的心脏磷酸蛋白质组和蛋白质组进行了表征。从27oC暴露于20oC24小时或一周后；或在从27oC适应到20oC的六周期间的多个时间点。我们的结果表明，冷暴露导致丝裂原活化蛋白激酶信号的增加，拉伸敏感途径的激活，通过泛素依赖性途径的细胞重塑，以及调节肌丝结构和功能的蛋白质（包括结蛋白和肌钙蛋白T）的磷酸化状态的变化。冷适应（2-6周）导致随着时间的推移电子传递链的多个组成部分减少，但是脂质运输的蛋白质增加，脂质代谢，将多不饱和脂肪酸掺入膜和蛋白质周转。例如,载脂蛋白C水平升高，前列腺素还原酶-3和过量基因座蛋白4，参与脂质运输，脂质代谢，和脂质膜重塑。ill的手术运动表明，冷适应过程中的氧气利用率降低。相对于体重和身体状况消耗的食物量均不受适应影响。这些结果表明，虽然氧气吸收减少，能量稳态得以维持。这项研究强调，斑马鱼对温度下降的反应是随时间变化的，并且对蛋白质组学反应的投资随着暴露时间的延长而增加。
