Liko Dritan, Slattery Matthew G, Heideman Warren
Department of Biomolecular Chemistry, School of Medicine, University of Wisconsin, Madison, Wisconsin 53705, USA.
J Biol Chem. 2007 Sep 7;282(36):26623-8. doi: 10.1074/jbc.M704762200. Epub 2007 Jul 6.
Transfer of quiescent Saccharomyces cerevisiae cells to fresh medium rapidly induces hundreds of genes needed for growth. A large subset of these genes is regulated via a DNA sequence motif known as the ribosomal RNA processing element (RRPE). However, no RRPE-binding proteins have been identified. We screened a panel of 6144 glutathione S-transferase-open reading frame fusions for RRPE-binding proteins and identified Stb3 as a specific RRPE-binding protein, both in vitro and in vivo. Chromatin immunoprecipitation experiments showed that glucose increases Stb3 binding to RRPE-containing promoters. Microarray experiments demonstrated that the loss of Stb3 inhibits the transcriptional response to fresh glucose, especially for genes with RRPE motifs. However, these experiments also showed that not all genes containing RRPEs were dependent on Stb3 for expression. Overall our data support a model in which Stb3 plays an important but not exclusive role in the transcriptional response to growth conditions.
将静止的酿酒酵母细胞转移至新鲜培养基中会迅速诱导数百个生长所需基因的表达。这些基因中的很大一部分是通过一种名为核糖体RNA加工元件（RRPE）的DNA序列基序来调控的。然而，尚未鉴定出RRPE结合蛋白。我们筛选了一组6144个谷胱甘肽S-转移酶-开放阅读框融合体以寻找RRPE结合蛋白，并在体外和体内均鉴定出Stb3是一种特异性的RRPE结合蛋白。染色质免疫沉淀实验表明，葡萄糖会增加Stb3与含RRPE启动子的结合。微阵列实验证明，Stb3的缺失会抑制对新鲜葡萄糖的转录反应，尤其是对于具有RRPE基序的基因。然而，这些实验还表明，并非所有含RRPE的基因在表达上都依赖于Stb3。总体而言，我们的数据支持一种模型，即Stb3在对生长条件的转录反应中起重要但非排他性的作用。
