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

海洋蕴藏着最大的未开发资源，可用于生物技术、农业和医药领域的新产品。冰结合蛋白（Ice-binding protein，IBPs）是一种广泛存在的蛋白质家族，它通过减少冰晶的形成，帮助适应低温的海洋微生物在低温下生存，并对微生物的冰环境进行改造，从而使其在低温下生存。潜在的应用包括控制食物中冰晶的形成，种植抗冻作物以及改善细胞和组织的保存以供医疗应用。然而，由于IBPs的多样性，不同异构体的功能需要确定，这将确定其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表征确定代表性IBPs在冷适应模式硅藻Fragilariopsis cylindrus中的功能。这种多产硅藻的基因组编码几个IBP基因，这些基因是差异表达的，基于靶向信号的初步数据表明，它们的蛋白质位于细胞的不同部位，这表明它们扮演着不同的角色。来自该项目的数据将为生物技术平台奠定基础，适应蛋白质为极地生物学提供新的见解，并测试和生产新的冷适应蛋白质。

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.