PUB1 - A MAJOR YEAST POLY(A)+ RNA-BINDING PROTEIN
PUB1 - A MAJOR YEAST POLY(A)+ RNA-BINDING PROTEIN
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DOI：
10.1128/mcb.13.10.6114
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发表时间：
1993-10-01
影响因子：
5.3
通讯作者：
DREYFUSS, G
中科院分区：
文献类型：
--
作者：
MATUNIS, MJ;MATUNIS, EL;DREYFUSS, G
RNA聚合酶II转录本的表达可在转录后水平受到RNA结合蛋白的调控。尽管在后生动物中已被广泛研究，但在酿酒酵母中被鉴定的RNA结合蛋白相对较少。在活的酿酒酵母细胞中，有三种主要蛋白质可通过紫外线照射与多聚（A）+RNA交联。它们是72 - kDa的多聚（A）结合蛋白以及60和50 kDa的蛋白质（S. A. Adam，T. Y. Nakagawa，M. S. Swanson，T. Woodruff和G. Dreyfuss，《分子细胞生物学》6：2932 - 2943，1986）。在此，我们描述60 - kDa的蛋白质，它是酿酒酵母中主要的多聚（A）+RNA结合蛋白之一。这种蛋白质，PUB1（多聚（U）结合蛋白1），通过固定化多聚（rU）亲和层析纯化，并制备了针对它的特异性单克隆抗体。紫外线交联表明PUB1在活细胞中与多聚（A）+RNA（mRNA或前体mRNA）结合，并且通过间接免疫荧光主要在细胞质中检测到它。PUB1基因被克隆和测序，发现该序列预测一种51 - kDa的蛋白质，它具有三个核糖核蛋白共有RNA结合结构域以及三个富含谷氨酰胺和天冬酰胺的辅助结构域。这种整体结构与黑腹果蝇elav基因产物、人类神经元抗原HuD以及细胞溶解性淋巴细胞蛋白TIA - 1的结构非常相似。这些蛋白质中的每一种在发育和分化中都可能通过影响RNA加工发挥重要作用。通过基因置换发现PUB1在酿酒酵母中是非必需的；然而，进一步的遗传分析应该会揭示这类RNA结合蛋白的重要特征。
The expression of RNA polymerase II transcripts can be regulated at the posttranscriptional level by RNA-binding proteins. Although extensively characterized in metazoans, relatively few RNA-binding proteins have been characterized in the yeast Saccharomyces cerevisiae. Three major proteins are cross-linked by UV light to poly(A)+ RNA in living S. cerevisiae cells. These are the 72-kDa poly(A)-binding protein and proteins of 60 and 50 kDa (S. A. Adam, T. Y. Nakagawa, M. S. Swanson, T. Woodruff, and G. Dreyfuss, Mol. Cell. Biol. 6:2932-2943, 1986). Here, we describe the 60-kDa protein, one of the major poly(A)+ RNA-binding proteins in S. cerevisiae. This protein, PUB1 [for poly(U)-binding protein 1], was purified by affinity chromatography on immobilized poly(rU), and specific monoclonal antibodies to it were produced. UV cross-linking demonstrated that PUB1 is bound to poly(A)+ RNA (mRNA or pre-mRNA) in living cells, and it was detected primarily in the cytoplasm by indirect immunofluorescence. The gene for PUB1 was cloned and sequenced, and the sequence was found to predict a 51-kDa protein with three ribonucleoprotein consensus RNA-binding domains and three glutamine- and asparagine-rich auxiliary domains. This overall structure is remarkably similar to the structures of the Drosophila melanogaster elav gene product, the human neuronal antigen HuD, and the cytolytic lymphocyte protein TIA-1. Each of these proteins has an important role in development and differentiation, potentially by affecting RNA processing. PUB1 was found to be nonessential in S. cerevisiae by gene replacement; however, further genetic analysis should reveal important features of this class of RNA-binding proteins.