N-terminal acetylation as a signal for protein degradation controlling plant development and stress responses

N-末端乙酰化作为蛋白质降解信号控制植物发育和胁迫反应

• 批准号: BB/M020568/1
• 负责人: Daniel Gibbs
• 金额: $ 51.92万
• 依托单位: University of Birmingham
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2015
• 资助国家: 英国
• 起止时间: 2015 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FM020568%2F1
• 关键词: terminal; acetylation; signal; protein; degradation

Unlike animals, plants cannot move, and have therefore evolved to grow and survive in constantly changing environments. Understanding the mechanisms that plants use to achieve this is critical if we are to develop superior crops to produce enough food to support a growing global population in the face of climate change. One way in which plants control their growth and respond to the environment is by regulating the stability of the proteins in their cells - plants need to precisely control when to get rid of a protein in order to successfully and rapidly respond to a wide range of signals. Protein degradation (proteolysis) in plants is important for controlling almost all aspects of plant life - for example, the sensing of and response to most plant hormones and a large number of external and internal signals (e.g. light and oxygen) is reliant on protein degradation. Therefore, increasing our understanding of the signals and mechanisms regulating protein stability is a major focus for plant science in order to identify targets that plant breeders and biotechnologists can focus on to develop improved crop varieties.This work will identify and characterize a new pathway for targeted protein degradation in plants. In this pathway, which was recently identified for the first time in yeast, degradation is initiated through the addition of a small molecule (acetyl) at the beginning (N-terminus) of a protein. Once a protein has been N-terminally acetylated, it can then be recognised by another type of protein that adds a second marker (ubiquitin), which acts as a signal for degradation by the cell. Our initial studies suggest that protein degradation via this pathway plays important roles during plant development and stress response (including the control of seed germination, drought response and chlorophyll content). This pathway therefore represents a promising new system for understanding and manipulating plant growth and survival, a key focus for future food security.We will investigate in detail how this pathway functions and what important aspects of plant life it controls. Studies will be carried out in the plant Arabidopsis - the 'lab rat' of the plant world - since it is much easier to grow and study compared to crop species, yet has all the same genes and mechanisms. We will develop and analyse Arabidopsis plants that have had the key components of this pathway removed (mutants) and ones which 'over produce' them, in order to understand what roles these factors play during normal growth and development. We will also perform studies to see where this pathway is working in the plant, both spatially (i.e. leaves vs roots?) and over time during the life cycle. Collectively this will allow us to dissect where and when this pathway is functional, and identify what key aspects of plant life it regulates. We will also perform biochemical analyses on protein 'targets' of the pathway, to show that their degradation is dependent on Nt-acetylation and subsequent addition of ubiquitin, which will provide important insight into the mechanisms and signals underpinning proteolysis via this pathway, and help guide future studies into identifying natural protein targets.Functional characterization of this novel pathway will greatly enhance our understanding of plant signalling and behaviour. Since these genes are conserved in important crop species - from barley to broccoli - this research will therefore help inform future studies into creating better, more efficient crop varieties. As well as uncovering an entirely new mechanism for regulating protein stability in plants, this work will also provide new insight into why some proteins are acetylated at their N-terminus. This modification is widely conserved in plants and animals, and was recently linked to human disease, but its functions are largely unknown. Thus our detailed studies will provide scientific insight that may also benefit human and medical research.

与动物不同，植物不能移动，因此已经进化到可以在不断变化的环境中生长和生存。如果我们要开发优质作物来生产足够的粮食来支持面临气候变化的不断增长的全球人口，那么了解植物实现这一目标的机制至关重要。植物控制生长和响应环境的一种方式是调节细胞中蛋白质的稳定性——植物需要精确控制何时去除蛋白质，以便成功、快速地响应各种信号。植物中的蛋白质降解（蛋白水解）对于控制植物生命的几乎所有方面都很重要 - 例如，大多数植物激素以及大量外部和内部信号（例如光和氧气）的感知和响应都依赖于蛋白质降解。因此，增加我们对调节蛋白质稳定性的信号和机制的理解是植物科学的一个主要关注点，以便确定植物育种家和生物技术学家可以重点关注的目标，以开发改良的作物品种。这项工作将确定并表征一条新的靶向途径植物中的蛋白质降解。最近首次在酵母中发现了这条途径，通过在蛋白质的开头（N 末端）添加小分子（乙酰基）来启动降解。一旦蛋白质被 N 末端乙酰化，它就可以被另一种类型的蛋白质识别，该蛋白质添加了第二个标记（泛素），作为细胞降解的信号。我们的初步研究表明，通过该途径的蛋白质降解在植物发育和胁迫反应（包括控制种子发芽、干旱反应和叶绿素含量）过程中发挥着重要作用。因此，该途径代表了一个有前途的理解和操纵植物生长和生存的新系统，这是未来粮食安全的一个关键焦点。我们将详细研究该途径如何发挥作用以及它控制植物生命的哪些重要方面。研究将在植物拟南芥（植物界的“实验室老鼠”）中进行，因为与农作物相比，拟南芥更容易种植和研究，但具有相同的基因和机制。我们将开发和分析已删除该途径关键成分的拟南芥植物（突变体）和“过度生产”这些成分的拟南芥植物，以了解这些因素在正常生长和发育过程中发挥的作用。我们还将进行研究，看看该途径在植物中的哪些位置发挥作用，无论是在空间上（即叶子还是根？）还是在生命周期中随着时间的推移。总的来说，这将使我们能够剖析该途径在何时何地发挥作用，并确定它调节植物生命的哪些关键方面。我们还将对该途径的蛋白质“靶标”进行生化分析，以表明它们的降解依赖于 Nt 乙酰化和随后泛素的添加，这将为通过该途径支持蛋白水解的机制和信号提供重要的见解，并帮助指导未来研究识别天然蛋白质靶标。这一新途径的功能表征将极大地增强我们对植物信号传导和行为的理解。由于这些基因在从大麦到西兰花的重要作物物种中是保守的，因此这项研究将有助于为未来的研究提供信息，以创造更好、更高效的作物品种。除了揭示植物中调节蛋白质稳定性的全新机制之外，这项工作还将为某些蛋白质在 N 末端乙酰化的原因提供新的见解。这种修饰在植物和动物中广泛保守，最近被认为与人类疾病有关，但其功能很大程度上未知。因此，我们的详细研究将提供科学见解，也可能有益于人类和医学研究。

项目成果

Disruption of the Na-Acetyltransferase NatB Causes Sensitivity to Reductive Stress in Arabidopsis thaliana.

Na-乙酰转移酶 NatB 的破坏导致拟南芥对还原应激敏感。

• DOI: http://dx.10.3389/fpls.2021.799954
• 发表时间: 2021
• 期刊: Frontiers in plant science
• 作者: Huber M

The Arabidopsis NOT4A E3 ligase promotes PGR3 expression and regulates chloroplast translation.

拟南芥 NOT4A E3 连接酶促进 PGR3 表达并调节叶绿体翻译。

• DOI: http://dx.10.1038/s41467-020-20506-4
• 发表时间: 2021
• 期刊: Nature communications
• 影响因子: 16.6
• 作者: Bailey M

Nt-acetylation-independent turnover of SQUALENE EPOXIDASE 1 by Arabidopsis DOA10-like E3 ligases.

拟南芥 DOA10 样 E3 连接酶对角鲨烯环氧酶 1 进行不依赖于 Nt 乙酰化的转换。

• DOI: http://dx.10.1093/plphys/kiad406
• 发表时间: 2023
• 期刊: Plant physiology
• 影响因子: 7.4
• 作者: Etherington RD

Learning To Breathe: Developmental Phase Transitions in Oxygen Status.

学习呼吸：氧状态的发育阶段转变。

• DOI: 10.1016/j.tplants.2016.11.013
• 发表时间: 2017-02-01
• 期刊: Trends in plant science
• 影响因子: 20.5
• 作者: M. Considine;P. Díaz‐Vivancos;P. Kerchev;S. Signorelli;P. Agudelo;D. Gibbs;C. Foyer
• 通讯作者: C. Foyer

Oxygen-dependent proteolysis regulates the stability of angiosperm polycomb repressive complex 2 subunit VERNALIZATION 2.

氧依赖性蛋白水解调节被子植物多梳抑制复合物 2 亚基 VERNALIZATION 2 的稳定性。

• DOI: http://dx.10.1038/s41467-018-07875-7
• 发表时间: 2018
• 期刊: Nature communications
• 影响因子: 16.6
• 作者: Gibbs DJ