Redd M J, Arnaud M B, Johnson A D
Department of Biochemistry and Biophysics, University of California, San Francisco, California 94143-0414, USA.
J Biol Chem. 1997 Apr 25;272(17):11193-7. doi: 10.1074/jbc.272.17.11193.
The Saccharomyces cerevisiae Tup1 protein is a member of a family of WD repeat containing proteins that are involved in repression of transcription. Tup1, along with the Ssn6 protein, represses a wide variety of genes in yeast including cell type-specific and glucose-repressed genes. Tup1 and Ssn6 are recruited to these specific gene sets by interaction with sequence-specific DNA binding proteins. In this work, a protein complex containing Ssn6 and Tup1 was purified to determine its composition. The size of the complex is estimated to be 440 kDa. Tup1 and Ssn6, which are both phosphoproteins, are the only proteins present in stoichiometric amounts in the complex. We also demonstrate that this purified complex represses transcription in an in vitro assay.
酿酒酵母Tup1蛋白是一个包含WD重复序列的蛋白质家族的成员，这些蛋白质参与转录抑制。Tup1与Ssn6蛋白一起，抑制酵母中的多种基因，包括细胞类型特异性基因和葡萄糖抑制基因。Tup1和Ssn6通过与序列特异性DNA结合蛋白相互作用被招募到这些特定的基因集。在这项工作中，纯化了一个包含Ssn6和Tup1的蛋白质复合物以确定其组成。该复合物的大小估计为440 kDa。Tup1和Ssn6都是磷蛋白，是该复合物中仅以化学计量存在的蛋白质。我们还证明，这种纯化的复合物在体外测定中抑制转录。
