Molecular characterisation of leader sequences which can also mediate ribosome 'skipping'

正常情况下，一个基因编码一种蛋白质。细胞内的许多过程需要在每个单独的细胞内存在多个不同的蛋白质--这些蛋白质可能相互作用，或者(在一个“途径”中)顺序地起作用，以执行特定的任务。我实验室的研究关注的是病毒--只有一个‘基因’--如何产生多种不同的蛋白质。我们发现了一种方法--我们称之为“核糖体跳过”--病毒可以通过这种方法完成这一壮举。这种方法已被证明非常适用于许多生物医学和生物技术目的，当一个人需要在同一细胞内表达多种不同的蛋白质时。实际上，人们可以通过将多个基因与我们描述的短序列(‘2A’)连接起来，将它们连接成一个基因。在每一条2A序列上，我们设计的新蛋白质(一种‘多蛋白’)被‘裂解’成其组成的单个蛋白质。幸运的是，这种方法适用于所有动物和植物细胞类型，这使得疾病的治疗、作物的基因操作等比试图将多个基因注入患者(人类基因疗法)或例如在植物中培育抗旱土豆要容易得多。我们已经发现了一种新型的2A序列，它不仅可以自我切割，而且还有另一种功能，可以将蛋白质引导到细胞内的不同位置。如果序列裂解，蛋白质就会位于细胞的某一部分：如果没有裂解，蛋白质就会进入细胞的不同部分。事实上，我们已经发现了144个新的序列-但许多都是密切相关的，所以我们不需要研究所有144-只有~35个具有代表性的序列。这是一个新的发现，我们想要做的一些工作将描述这个系统的生物学特征：这些不同的2A的序列如何与它们拥有的两种不同的特性(细胞内的自我切割/蛋白质靶向)相关。这项工作的另一个方面是看看这些序列是否在植物和酵母中起作用。如果是这样的话，这些序列的潜在用途就会大大扩大。我们希望开发这些序列作为工具，供其他科学家使用，使他们能够对疾病的新疗法、新的生物技术产品和工艺进行研究。

Normally one gene encodes one protein. Many processes within the cell require multiple, different, proteins to present within each individual cell - these proteins may interact with each other ,or, act sequentially (in a 'pathway' to perform a specific task. The research in my laboratory has been concerned with how viruses - with just one 'gene' - can generate multiple, different, proteins. We discovered one method - which we called 'ribosome skipping' - by which viruses can accomplish this feat. This method has proved to be very adaptable for many biomedical and biotechnological purposes when one needs to express multiple, different, proteins within the same cell. In effect, one can concatenate multiple genes into one by linking them with the short sequence ('2A') we characterised. At each 2A sequence, the new protein we have designed (a 'polyprotein') is 'cleaved' apart into it's constituent individual proteins. Fortunately, this method works in all animal and plant cell-types, which makes treatment of diseases, the genetic manipulation of crops etc. much easier than trying to introduce multiple genes into the patient (human gene therapy) or in the case of plants, for example, to make drought-resistant potatoes. We have discovered a new type of 2A sequence that can not only cleave itself, but has another function to direct the protein to a different site within the cell. If the sequence cleaves the protein becomes located in one part of the cell: if it doesn't cleave the protein goes to a different part of the cell. In fact, we have discovered 144 new sequences - but many are closely related so we don't need to study all 144 - just ~35 representative sequences. This is a new discovery and some of the work we want to do will characterise the biology of this system: how the sequence of these different 2As relates to the two different properties (self-cleaving / protein targeting within the cell) they have. The other aspect of the work is to see if these sequences work in plants and yeast. If this is so, then the potential uses of these sequences is dramatically expanded. We want to develop these sequences as tools for other scientists to use, to enable them to conduct their research into new cures for disease, for new biotechnological products and processes.