Ice-binding proteins (IBPs) in cold-adapted diatoms - implications for survival under freezing temperatures

海洋拥有最大的未开发资源，用于生物技术、农业和医药的新产品。许多具有巨大潜力的有价值的产品已经从适应冷的海洋微生物中分离出来，因为它们占据着极端的环境，需要蛋白质在低温下发挥作用。无处不在的冰结合蛋白(IBPs)家族通过减少冰晶的形成来帮助适应冷的生物在较低的温度下生存，如果是微生物，则通过重塑它们的冰雪环境来帮助它们在较低的温度下生存。潜在的应用包括控制食品中的冰晶形成，种植抗霜冻的作物，以及为医疗应用改善细胞和组织的保存。然而，由于IBPs的多样性，需要确定不同亚型的功能，这将决定它们在生物技术中的应用。为了解决这个问题，本项目将通过反向遗传学和生化特性确定具有代表性的IBPs在冷适应模式硅藻Fragilariopsis圆柱体中的功能。这种多产硅藻的基因组编码了几个差异表达的IBP基因，基于靶向信号的初步数据表明，它们的蛋白质定位于细胞的不同部分，这表明它们发挥着不同的作用。来自该项目的数据将为生物技术平台表征冷适应蛋白奠定基础，为极地生物的生物学提供新的见解，并测试和生产新的冷适应蛋白。

The ocean harbours the largest untapped resource for novel products used in biotechnology, agriculture and medicine. Many valuable products with great potential have been isolated from cold-adapted marine microbes as they occupy extreme environments, which require proteins to function at low temperatures.The ubiquitous family of ice-binding proteins (IBPs) helps cold-adapted organisms to survive at lower temperatures by reducing ice-crystal formation, and in case of microbes by reshaping their icy surroundings. Potential applications include controlling ice-crystal formation in food, growing frost-resistant crops and improving preservation of cells and tissues for medical applications. However, as IBPs are diverse, the function of different isoforms needs to be determined, which will define their applications in biotechnology.To address this question, this project will determine the function of representative IBPs in the cold-adapted model diatom Fragilariopsis cylindrus through reverse genetics and biochemical characterisation. The genome of this prolific diatom encodes several IBP genes, which are differentially expressed, and preliminary data based on targeting signals imply that their proteins are localised in different parts of the cell, which suggests that they perform different roles.Data from this project will lay the foundation for a biotechnology platform to characterise cold-adapted proteins for providing new insights into the biology of polar organisms and to test and produce novel cold-adapted proteins.