Cyclic di-GMP in the control of multicellular differentiation in antibiotic-producing bacteria Streptomyces.

环状二-GMP 控制抗生素生产细菌链霉菌的多细胞分化。

• 批准号: 282982160
• 负责人: Professorin Dr. Natalia Tschowri
• 金额: --
• 依托单位: Institut für Mikrobiologie (ifmb)
• 依托单位国家: 德国
• 项目类别: Independent Junior Research Groups
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/282982160?language=en
• 关键词: Cyclic; di; GMP; control; multicellular

Streptomyces are the most abundant source of clinically important antibiotics and other natural products used in human medicine. The production of these secondary metabolites is temporally and genetically coordinated with a complex developmental life cycle involving growth as vegetative mycelium of branching hyphae and dispersion via spores formed on specialized reproductive structures called aerial hyphae. We have recently discovered that the nucleotide second messenger c-di-GMP, which is produced by GGDEF-domain proteins and degraded by either EAL- or HD-GYP-domain proteins, plays a crucial role in controlling Streptomyces development. We identified the developmental master regulator BldD as a first c-di-GMP effector in the genus Streptomyces and demonstrated that BldD binds a tetrameric form of c-di-GMP, which results in transcription factor dimerization and effective repression of sporulation genes during vegetative growth. However, our knowledge about c-di-GMP signalling components in Streptomyces is still very limited. The aim of the proposed work is to systematically analyse and characterize in molecular detail the functions and regulatory aspects of all GGDEF, EAL, HD-GYP domain proteins in Streptomyces venezuelae. My initial data show that four of the c-di-GMP metabolizing enzymes have an impact on differentiation and are under the control of multiple developmental regulators but the underlying mechanisms are not understood. Moreover, in my pull-down experiments, which led to the identification of BldD as a c-di-GMP effector protein, multiple other putative c-di-GMP binding proteins were enriched. To validate these candidates as c-di-GMP effectors and to uncover their function(s) is planned in this proposal. Altogether, the proposed research aims at finding the mechanism(s) of action of these c-di-GMP signalling components, elucidation of their position(s) in cellular regulatory pathways and uncovering of their physiological role(s). This work will greatly improve our understanding of Streptomyces physiology and c-di-GMP signalling in a new physiological context involving multicellular differentiation and secondary metabolite production and can contribute to a better exploitation of genetic engineering in Streptomyces for the production of antibiotics.

链霉菌是临床上重要的抗生素和其他用于人类医学的天然产品的最丰富来源。这些次生代谢物的产生在时间上和遗传上与复杂的发育生命周期相协调，包括作为分枝菌丝的营养菌丝体生长，以及通过在被称为气生菌丝的特殊生殖结构上形成的孢子传播。我们最近发现，核苷酸第二信使c-di-GMP是由GGDEF结构域蛋白产生的，被EAL-或HD-Gyp结构域蛋白降解，在控制链霉菌生长方面起着至关重要的作用。我们鉴定了发育主控基因BldD是链霉菌属中第一个c-di-GMP效应子，并证明BldD结合了四聚体形式的c-di-GMP，从而导致转录因子二聚化和营养生长过程中产孢子基因的有效抑制。然而，我们对链霉菌中c-di-GMP信号成分的了解仍然非常有限。这项工作的目的是系统地分析和表征维尼链霉菌中所有GGDEF、EAL、HD-GYP结构域蛋白的功能和调控方面的分子细节。我的初步数据显示，四种c-di-GMP代谢酶对分化有影响，并受到多种发育调节因子的控制，但其潜在机制尚不清楚。此外，在我的下拉实验中，BldD被确定为c-di-GMP效应蛋白，其他许多假定的c-di-GMP结合蛋白也得到了丰富。本提案计划验证这些候选基因作为c-di-GMP效应子并揭示其功能(S)。总之，建议的研究旨在发现这些c-di-GMP信号成分的作用机制(S)，阐明它们在细胞调控途径中的位置(S)，并揭示它们的生理作用(S)。这项工作将极大地提高我们在涉及多细胞分化和次生代谢物产生的新的生理背景下对链霉菌的生理学和c-di-GMP信号的理解，并有助于更好地利用链霉菌的基因工程来生产抗生素。