Cell Cycle-Specific Regulation of Nucleotide Excision Repair in S. Cerevisiae

酿酒酵母中核苷酸切除修复的细胞周期特异性调控

• 批准号: RGPIN-2014-05285
• 负责人: Drobetsky, Elliot
• 金额: $ 2.55万
• 依托单位: Université de Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=629903
• 关键词: Cell; Cycle; Specific; Regulation; Nucleotide

Exposure to UV rays from the sun can severely damage the DNA which makes up our genes, and this can lead to the formation of genetic changes called "mutations" in our skin cells. Such mutations are highly undesirable because they represent the primary cause of malignant melanoma, an extremely deadly form of skin cancer that occurs with alarming frequency in young Canadian adults. Fortunately our cells possess a biochemical mechanism, called "Nucleotide Excision Repair" (abbreviated NER) which is able to completely reverse the damage to our genes caused by UV, thereby preventing skin cancer-causing mutations from developing in the first place. Studies from my research group previously showed for the first time that a key protein called "ATR kinase" must be present in skin cells in sufficient amounts to ensure that the NER mechanism operates efficiently. As such, our major experimental goal has been to discover precisely how ATR kinase acts to stimulate NER. However, for various technical reasons, this goal is extremely difficult to achieve using investigations on human cells. In the current grant application, we therefore propose to employ yeast cells for such studies, since these cells are far simpler to manipulate and much better characterized than human cells. More importantly yeast represents a very accurate model for studying biochemical mechanisms in humans. Indeed (i) yeast cells contain a protein called "Mec1 kinase" which works in the same way as ATR kinase in human cells and (ii) in general the yeast and human NER mechanisms bear remarkably similarity. Completion of the proposed studies would represent an important contribution to basic biological research by providing fundamental new information about how yeast cells control the NER pathway, and hence how this particular organism removes genetic damage caused by UV rays. In addition our research conducted in yeast would be expected to provide important clues regarding how the human NER process works. This will certainly benefit Canadians because, as alluded to above, NER is a major mechanism which protects humans from malignant melanoma, a dreaded disease that currently plagues our population.

暴露在太阳的紫外线下会严重损害构成我们基因的DNA，这可能导致我们皮肤细胞中形成被称为“突变”的基因变化。这种突变是非常不受欢迎的，因为它们是恶性黑色素瘤的主要原因，恶性黑色素瘤是一种极其致命的皮肤癌，在加拿大年轻人中发病率惊人。幸运的是，我们的细胞拥有一种叫做“核苷酸切除修复”（简称NER）的生化机制，它能够完全逆转紫外线对我们基因造成的损害，从而从一开始就防止皮肤癌突变的发生。我课题组之前的研究首次表明，皮肤细胞中必须存在一种名为“ATR激酶”的关键蛋白，其数量必须足够，才能确保NER机制有效运作。因此，我们的主要实验目标是精确地发现ATR激酶如何刺激NER。然而，由于各种技术原因，这一目标很难通过对人类细胞的研究来实现。因此，在目前的拨款申请中，我们建议使用酵母细胞进行此类研究，因为这些细胞比人类细胞更容易操作并且具有更好的特征。更重要的是，酵母是研究人体生化机制的一个非常准确的模型。事实上(i)酵母细胞含有一种叫做“Mec1激酶”的蛋白质，其作用方式与人类细胞中的ATR激酶相同；（ii）一般来说，酵母和人类的NER机制具有显著的相似性。拟议研究的完成将为基础生物学研究做出重要贡献，提供酵母细胞如何控制NER通路的基本新信息，以及这种特殊生物体如何消除紫外线引起的遗传损伤。此外，我们在酵母中进行的研究将有望提供关于人类NER过程如何工作的重要线索。这当然会使加拿大人受益，因为，正如上面提到的，NER是保护人类免受恶性黑色素瘤的主要机制，恶性黑色素瘤是目前困扰我们人口的可怕疾病。