Molecular mechanisms of eukaryotic ribosome assembly

了解单个细胞获得基因突变是如何通过与正常健康细胞竞争来驱动癌症的，这是癌症生物学中的一个关键问题。遗传性疾病Shwachman-Diamond综合征（SDS）是解决这个问题的一个很好的模型，因为受该疾病影响的个体具有发展血癌的倾向，并且起始遗传病变是已知的。在我的实验室中，MRC支持的工作将SDS的主要缺陷定义为核糖体组装受损，核糖体是分子纳米机器，它在我们的细胞中制造所有蛋白质。然而，核糖体组装的基本机制以及该过程中的缺陷如何促进癌症仍然知之甚少。这些都是重要的问题，因为核糖体蛋白基因的突变现在被认为是人类癌症中常见的脆弱性。然而，在这一领域取得进展有两个主要障碍。首先是缺乏天然人类60 S核糖体组装中间体的高分辨率结构，这些中间体是高度动态的并且通常是瞬时的。第二个障碍是在人类疾病状态下体内追踪血液干细胞克隆的固有困难。为了克服这些障碍，我们将使用最新的成像技术系统地确定关键的天然60 S核糖体亚基成熟中间体的结构。此外，我们将使用造血干细胞中的获得性突变作为内源性条形码工具，以确定核糖体组装中的缺陷如何通过与正常对应物竞争来促进癌症的发展。

Understanding how the acquisition of a genetic mutation by a single cell drives a cancer by outcompeting its normal healthy cell counterparts is a key question in cancer biology. The genetic disorder Shwachman-Diamond syndrome (SDS) is an excellent model with which to address this question as individuals affected by the disorder have an increased propensity to develop blood cancers and the initiating genetic lesions are known. MRC-supported work in my lab defined the primary defect in SDS as impaired assembly of ribosomes, molecular nanomachines that make all the proteins in our cells. However, the basic mechanisms of ribosome assembly and how defects in this process promote cancer remain poorly understood. These are important questions, as mutations in ribosomal protein genes are now recognised as a common vulnerability in human cancers. However, there are two major barriers to progress in the field. The first is the lack of high-resolution structures of native human 60S ribosome assembly intermediates, which are highly dynamic and often transient. The second barrier is the inherent difficulty in tracking blood stem cell clones in vivo in human disease states. To overcome these obstacles, we will systematically determine the structures of key native 60S ribosomal subunit maturation intermediates using the latest imaging technologies. Furthermore, we will use acquired mutations in blood stem cells as an endogenous barcoding tool to determine how defects in ribosome assembly promote the development of cancer by outcompeting their normal counterparts.