Characterization of lipid signaling altered by T3S effector AvrBsT

描述（由申请人提供）：植物和动物的细菌病原体使用III型分泌（T3 S）系统和效应蛋白底物来改变真核生物生理学，以促进细菌增殖和宿主定殖。植物病原细菌中的T3 S效应子（~20-30种蛋白质）的大库预测植物信号级联中的多个节点被靶向。然而，这些T3 S效应蛋白操纵植物生理的植物靶标和生化机制的身份知之甚少。广泛的表型研究支持了许多T3 S效应子抑制植物免疫系统在组织中定殖的概念。这阐明了基础防御反应和抗性（R）蛋白介导的先天免疫反应在控制植物界细菌感染结果中的重要性。了解植物免疫力是如何调节的，以及细菌病原体是如何操纵它们的宿主的，是预防和消除植物病害所需的基础知识。该项目的长期目标是阐明植物如何整合脂质信号以应对细菌感染。两个保守的真核生物蛋白-SOBER 1，脂肪酶和CIP，推定的载脂蛋白-已被鉴定和证明是重要的调节剂的先天免疫反应在植物中。将使用拟南芥病理系统进行全面的遗传和生化研究，以表征SOBER 1和CIP底物特异性，并确定这些蛋白质在细菌感染期间控制磷脂代谢和信号传导的机制。研究还旨在确定病原体T3 S效应子AvrBsT扰乱受感染植物细胞内脂质稳态的生化机制。这项工作有望为植物控制脂质代谢和响应病原体攻击的信号传导的生化机制提供基本的见解。越来越多的证据表明，在植物和动物中脂质代谢和免疫之间的相互作用表明，有关脂质信号如何启动和终止的基本知识对于充分了解真核生物中免疫系统如何调节至关重要。 公共卫生相关性：了解植物免疫力是如何调节的，以及细菌病原体是如何操纵它们的宿主的，是预防和消除植物病害所需的基础知识。

DESCRIPTION (provided by applicant): Bacterial pathogens of plant and animals use the type III secretion (T3S) system and effector protein substrates to alter eukaryotic physiology to promote bacterial multiplication and host colonization. The large repertoire of T3S effectors (~20-30 proteins) in plant pathogenic bacteria predicts that multiple nodes in plant signaling cascades are being targeted. The identity of the plant targets and the biochemical mechanisms by which these T3S effector proteins manipulate plant physiology however are poorly understood. Extensive phenotypic studies support the concept that many of the T3S effectors suppress the plant immune system to colonize tissues. This illuminates the importance of basal defense responses and resistance (R) protein-mediated innate immune responses in controlling the outcome of bacterial infections in the plant kingdom. Understanding how plant immunity is regulated and how bacterial pathogens manipulate their hosts is fundamental knowledge required for the prevention and elimination of plant disease. The long-term goal of this project is elucidate how plants integrate lipid signals to respond to bacterial infection. Two conserved eukaryotic proteins - SOBER1, a lipase and CIP, a putative apolipoprotein - have been identified and shown to be important regulators of innate immune responses in plants. Comprehensive genetic and biochemical studies will be performed using the Arabidopsis pathosystem to characterize SOBER1 and CIP substrate specificity and to determine the mechanisms by which these proteins control phospholipid metabolism and signaling during bacterial infection. Studies will also be aimed to determine the biochemical mechanisms by which the pathogen T3S effector AvrBsT perturbs lipid homeostasis within infected plant cells. This work is expected to provide fundamental insight to the biochemical mechanisms used by plants to control lipid metabolism and signaling in response to pathogen attack. The growing body of evidence suggesting an interplay between lipid metabolism and immunity in both plants and animals indicates that fundamental knowledge about how lipid signals are initiated and terminated will be essential to fully understand how the immune system is regulated in eukaryotes. PUBLIC HEALTH RELEVANCE: Understanding how plant immunity is regulated and how bacterial pathogens manipulate their hosts is fundamental knowledge required for the prevention and elimination of plant disease.