Bae Nancy S, Seberg Andrew P, Carroll Leslie P, Swanson Mark J
Department of Biochemistry, Arizona College of Osteopathic Medicine, Midwestern University, Glendale, Arizona 85308.
Department of Biological Science, Florida State University, Tallahassee, Florida 32306-4295.
G3 (Bethesda). 2017 Apr 3;7(4):1061-1084. doi: 10.1534/g3.116.037416.
The yeast responds to amino acid deprivation by activating a pathway conserved in eukaryotes to overcome the starvation stress. We have screened the entire yeast heterozygous deletion collection to identify strains haploinsufficient for growth in the presence of sulfometuron methyl, which causes starvation for isoleucine and valine. We have discovered that cells devoid of are sensitive to sulfometuron methyl, and loss of heterozygosity at the locus can complicate screening the heterozygous deletion collection. We identified 138 cases of loss of heterozygosity in this screen. After eliminating the issues of the loss of heterozygosity, strains isolated from the collection were retested on sulfometuron methyl. To determine the general effect of the mutations for a starvation response, SMM-sensitive strains were tested for the ability to grow in the presence of canavanine, which induces arginine starvation, and strains that were were also tested for growth in the presence of ethionine, which causes methionine starvation. Many of the genes identified in our study were not previously identified as starvation-responsive genes, including a number of essential genes that are not easily screened in a systematic way. The genes identified span a broad range of biological functions, including many involved in some level of gene expression. Several unnamed proteins have also been identified, giving a clue as to possible functions of the encoded proteins.
酵母通过激活真核生物中保守的一条途径来应对氨基酸剥夺，以克服饥饿压力。我们筛选了整个酵母杂合缺失文库，以鉴定在存在甲磺隆甲酯的情况下生长单倍体不足的菌株，甲磺隆甲酯会导致异亮氨酸和缬氨酸饥饿。我们发现缺失[具体基因名称未给出]的细胞对甲磺隆甲酯敏感，并且在[具体基因名称未给出]位点的杂合性丧失会使杂合缺失文库的筛选变得复杂。我们在该筛选中鉴定出138例杂合性丧失的情况。在消除[具体基因名称未给出]杂合性丧失的问题后，从文库中分离出的菌株在甲磺隆甲酯上重新进行测试。为了确定突变对饥饿反应的总体影响，对SMM敏感的菌株测试其在刀豆氨酸存在下生长的能力，刀豆氨酸会诱导精氨酸饥饿，并且对缺失[具体基因名称未给出]的菌株也测试其在乙硫氨酸存在下生长的能力，乙硫氨酸会导致甲硫氨酸饥饿。我们研究中鉴定出的许多基因以前未被鉴定为饥饿反应基因，包括一些不容易以系统方式筛选的必需基因。鉴定出的基因涵盖广泛的生物学功能，包括许多参与某种程度基因表达的基因。还鉴定出了几种未命名的蛋白质，这为所编码蛋白质的可能功能提供了线索。
