Function and structure of specialised ribosomes in the testis

动物、植物和细菌中的所有蛋白质都是由一种叫做核糖体的机器制造的。这是任何细胞中最大的复合体之一，由大约90种不同的成分组成。直到最近，人们还认为所有的核糖体都是一样的，它们负责合成蛋白质而不发挥任何调节作用。但是，果蝇基因和由核糖体成分突变引起的人类疾病表明，并非每种成分都是必要的。特定成分的突变导致特定疾病和发育问题。例如，有些成分在发育过程中很重要（如小鼠神经系统），而其他成分在病毒感染过程中很重要。因此，目前的想法是，一些核糖体成分可以被其他成分取代，从而允许核糖体控制它制造的蛋白质。这被称为“核糖体特化”。然而，我们还不了解它是如何工作的，以及它在功能上的后果是什么。我们最近的实验和其他研究人员的数据表明，核糖体的这种特化在睾丸中特别普遍和广泛。特别是，我们已经看到了果蝇睾丸中核糖体成分的差异。由于核糖体的蛋白质生产在精子产生过程中特别重要，我们假设核糖体组成的变化在精子产生过程中很重要。果蝇核糖体成分的突变导致雄性不育。因此，了解这种核糖体专门化有可能为人类男性不育的原因提供深入了解。该项目旨在了解睾丸中这些特殊核糖体的组成以及组成的改变如何影响蛋白质的产生。我们将通过理解1)组成的变化如何影响核糖体的整体形状和结构来做到这一点；2)专门的核糖体如何控制特定蛋白质的产生；3)睾丸中核糖体在精子发育过程中的变化。通过阐明这两种下游效应，我们将能够理解特化核糖体的重要性。这个项目是两位专家在两个不同领域的新合作。这使我们能够使用最合适和最先进的方法来解决特化核糖体的结构和功能，包括：-果蝇遗传学：果蝇睾丸是研究特化核糖体的一个很好的模型，因为我们可以对果蝇进行基因修饰并解剖睾丸以产生足够的材料进行测序和结构分析。-低温电子显微镜，使我们能够以接近原子的分辨率对核糖体进行成像。-下一代测序：为了描述不同的特化核糖体如何影响蛋白质合成，我们将使用一种新的测序方法来识别特化核糖体解码为蛋白质的所有rna。这是一种高通量技术，可以观察细胞中发生的所有蛋白质生产。这是一个非常新颖的研究领域，这个项目有可能改变我们对如何控制蛋白质生产的看法。它也有可能为针对一系列人类疾病和失调的治疗提供基础。一组疾病是由不同核糖体成分的突变引起的，称为核糖体病，包括Diamond-Blackfan病。通过了解核糖体组成的变化和不同成分的功能重要性，我们将阐明这些核糖体病的原因。

All proteins in animals, plants and bacteria are made by a machine called the ribosome. This is one of the largest complexes in any cell, consisting of ~90 different components. Until recently it was thought that all ribosomes were the same, responsible for synthesising protein without exerting any regulatory activity. But fruit fly genetics and human diseases caused by mutations in the ribosome components suggest that not every component is essential all of the time. Mutations to specific components result in specific disease and developmental problems. For example, some components are important during development (e.g. mouse nervous system) and others during viral infection. So the current thinking is that some ribosomal components can be substituted by alternative components, allowing the ribosome to control which protein it makes. This is termed 'ribosome specialisation'. However, we do not yet understand how this works and what the functional consequences are.Our recent experiments and data from other researchers indicate that this specialisation of the ribosome is particularly common and extensive in the testis. In particular, we have seen differences in the components within the ribosomes in the fruit fly testis. Since protein production by the ribosome is particularly important during sperm production, we hypothesise that changes in ribosome composition are important during sperm production. Mutations in ribosomal components in the fruit fly result in male sterility. Therefore, understanding this ribosome specialisation has the potential to provide insight into the causes of male infertility in humans. This project aims to understand the composition of these specialised ribosomes in the testis and how the alterations in composition affect the production of protein. We will do this by understanding 1) how changes in composition affect the overall shape and structure of the ribosome; 2) how specialised ribosomes control the production of specific proteins; and 3) how the ribosome changes during sperm development in the testis. By shedding light into these two downstream effects we will be able understand the importance of specialised ribosomes. This project is a new collaboration between two experts in two different fields. This allows us to use the most appropriate and cutting-edge approaches to tackle the structure and function of specialised ribosome, including:- Fruit fly genetics: The fruit fly testis is a great model for studying specialised ribosomes because we can genetically modify the flies and dissect testes to generate enough material for sequencing and structural analysis. - Cryo-electron microscopy, which allows us to image ribosomes at a close-to-atomic resolution. - Next Generation Sequencing: To characterise how protein synthesis is affected by the different specialised ribosomes, we will use a novel sequencing approach to identify all the RNAs that the specialised ribosomes are decoding into protein. This is a high-throughput technique to look at all the protein production taking place in cells. This is a very novel area of research and this project has the potential to change the way we think about how protein production is controlled. It also has the potential to provide a basis for therapeutic targeting of a range of human diseases and disorders. A group of diseases are caused by mutations to the different ribosomal components, termed ribosomopathies, including Diamond-Blackfan disease. By understanding changes in ribosome composition and the functional importance of the different components we will shed light on the causes of these ribosomopathies.