Role of SPH-3 a catalytically inactive serine proteinase homologue protein in insect immune defences

SPH-3（一种催化失活丝氨酸蛋白酶同源蛋白）在昆虫免疫防御中的作用

• 批准号: BB/E022529/1
• 负责人: Stuart Reynolds
• 金额: $ 42.04万
• 依托单位: University of Bath
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2007
• 资助国家: 英国
• 起止时间: 2007 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FE022529%2F1
• 关键词: Role; SPH; catalytically; inactive; serine

Better knowledge of insect immune systems has also led in recent years to important advances in understanding human immunity. Nevertheless, the signaling systems used in recognising and responding to bacteria remain poorly understood. A protein, SPH-3, present in the hemolymph (blood) of a large experimental model insect, Manduca sexta, plays a key role in this insect's ability to defend itself against infection by pathogenic bacteria. SPH-3 is a member of the serine proteinase familiy of proteins, but is catalytically inactive. It appears to play a signalling role in the insect's immune system, but its precise role is unclear. The proposed work seeks to determine with which other immune system proteins SPH-3 interacts, and how it exerts its downstream effects. The work will lead to enhanced understanding of insect immune systems, and will thereby provide information that may also enable better understanding of immunity in man and other mammals. The work is of wide biological interest in that it concerns the biological functions of an enzyme that has evolved to gain a signaling function, but in doing so has lost its original catalytic activity. Further, since the protein in question is the target of a major virulence gene of a widely used agent of biological insect pest control, there may also be applied spin-off.

近年来，对昆虫免疫系统的更好了解也导致了对人类免疫的理解取得了重要进展。然而，用于识别和响应细菌的信号系统仍然知之甚少。一种蛋白质SPH-3存在于一种大型实验模型昆虫--天蛾的血淋巴（血液）中，在这种昆虫抵御病原菌感染的能力中起着关键作用。SPH-3是蛋白质的丝氨酸蛋白酶家族的成员，但无催化活性。它似乎在昆虫的免疫系统中发挥信号作用，但其确切作用尚不清楚。这项工作旨在确定SPH-3与其他免疫系统蛋白质的相互作用，以及它如何发挥其下游作用。这项工作将导致增强对昆虫免疫系统的理解，从而提供信息，也可以更好地了解人类和其他哺乳动物的免疫力。这项工作具有广泛的生物学意义，因为它涉及一种酶的生物学功能，这种酶已经进化到获得信号功能，但在这样做的过程中失去了其原始的催化活性。此外，由于所述蛋白质是广泛使用的生物昆虫害虫控制剂的主要毒力基因的靶标，因此也可以应用副产物。