Identifying Gene Functions at Late Endosome and Lysosome in Yeast

描述（由申请人提供）：正确分选和向降解溶酶体输送分子是所有真核细胞的基本特征。酿酒酵母的晚期核内体和液泡在功能上与哺乳动物的晚期核内体和溶酶体相当；它的羧基肽酶Y （CPY）空泡传递途径与哺乳动物细胞中的甘露糖-6-磷酸途径相似。酵母提供了传统和分子遗传学工具的优势；在溶酶体运输中发现的大部分酵母菌基因在人类中有同源物。对液泡运输和功能相关基因的两个单独的基因组宽筛选结果使我们发现：1)几个先前未被表征的基因在核内体和液泡界面起作用（ENV基因）；2)一小组参与液泡运输和功能的基因，当它们被删除时，会对湿霉素B产生严重的超敏反应（HHY基因）。此外，所有hhy突变体还表现出药物超敏性，这表明TOR激酶信号通路存在缺陷，TOR激酶是通过营养和生长因子感知细胞生长和增殖的主要调节因子。在这个竞争性更新中，我们提出了对新基因ENV9的多方面表征，该基因与人类视黄醇脱氢酶RDH12具有重要的同一性，RDH12是一个与早发性视网膜变性有关的基因。我们还建议通过酵母遗传学，分子和显微镜方法探索液泡运输，TOR激酶信号传导和潮霉素B超敏反应的界面。在这个地区的提案中，固有的目标是继续发展少数民族博士后研究人员，并在一个综合性的西班牙裔服务研究所继续对本科生和硕士生进行富有成效的研究培训。溶酶体蛋白酶和货物的错误定位与溶酶体贮积病和阿尔茨海默病（AD）有关。特别是在内核体到溶酶体运输阶段的缺陷已被认为是青少年和老年神经退行性疾病的可能潜在机制。TOR激酶信号的过度激活与良性和恶性肿瘤的发生以及包括糖尿病和肥胖在内的代谢性疾病有关。

DESCRIPTION (provided by applicant): Correct sorting and vesicular trafficking of molecules to the degradative lysosome is an essential feature of all eukaryotic cells. The late endosome and vacuole of the yeast Saccharomyces cerevisiae are functionally equivalent to the mammalian late endosome and lysosome; its carboxy peptidase Y (CPY)-pathway of vacuolar delivery parallels the mannose-6-phosphate pathway in mammalian cells. Yeast offers the advantage of both conventional and molecular genetics tools; large majority of yeast genes identified in lysosomal trafficking have orthologues in humans. Results of two separate genome wide screens for vacuolar trafficking and function related genes have led us to 1)several previously uncharacterized genes that have a role at endosome and vacuole interface (ENV genes), 2) a small set of genes involved in vacuolar trafficking and function that confer severe hypersensitivity to hygromycin B when deleted (HHY genes). Furthermore, all hhy mutants also showed drug hypersensitivities indicative of defective TOR kinase signaling, a master regulator of cell growth and proliferation through nutrient and growth factor sensing. In this competitive renewal, we propose multifaceted characterization of the novel gene ENV9 which has significant identity to human retinol dehydrogenase RDH12 - a gene implicated in early onset retinal degeneration. We also propose to explore the interface of vacuolar trafficking, TOR kinase signaling, and hygromycin B hypersensitivity by yeast genetics, molecular, and microscopic approaches. Inherent in this AREA proposal, is the aim to continue development of a minority post-doctoral researcher and continue productive research training of undergraduate and Master's students within a comprehensive Hispanic Serving Institute. Mislocalization of lysosomal proteases and cargo is associated with Lysosomal Storage Diseases and Alzheimer's disease (AD). Defects specifically at the late endosome to lysosome stage of trafficking have emerged as the possible underlying mechanism in both juvenile and aging neurodegeneration diseases. Hyper activation of TOR kinase signaling is associated with benign and malignant tumorigenesis, as well as with metabolic diseases including diabetes and obesity. PUBLIC HEALTH RELEVANCE: The proposed research is relevant to public health issues associated with both juvenile and late onset neurodegeneration as manifested in Lysosomal Storage Diseases and Alzheimer's disease, respectively. It is also relevant to public health issues associated with tumorigenesis and metabolic diseases including diabetes and obesity.