Dheur Sonia, Vo Le Thuy Anh, Voisinet-Hakil Florence, Minet Michèle, Schmitter Jean-Marie, Lacroute François, Wyers Françoise, Minvielle-Sebastia Lionel
Institut de Biochimie et Génétique Cellulaires, CNRS, UMR 5095, 1 Rue Camille Saint Saëns, 33077 Bordeaux cedex, France.
EMBO J. 2003 Jun 2;22(11):2831-40. doi: 10.1093/emboj/cdg253.
Eukaryotic RNA polymerase II transcribes precursors of mRNAs and of non-protein-coding RNAs such as snRNAs and snoRNAs. These RNAs have to be processed at their 3' ends to be functional. mRNAs are matured by cleavage and polyadenylation that require a well-characterized protein complex. Small RNAs are also subject to 3' end cleavage but are not polyadenylated. Here we show that two newly identified proteins, Pti1p and Ref2p, although they were found associated with the pre-mRNA 3' end processing complex, are essential for yeast snoRNA 3' end maturation. We also provide evidence that Pti1p probably acts by uncoupling cleavage and polyadenylation, and functions in coordination with the Nrd1p-dependent pathway for 3' end formation of non-polyadenylated transcripts.
真核生物RNA聚合酶II转录mRNA前体以及非蛋白质编码RNA，如小核RNA（snRNA）和小核仁RNA（snoRNA）。这些RNA必须在其3'端进行加工才能发挥功能。mRNA通过切割和聚腺苷酸化成熟，这需要一个特征明确的蛋白质复合物。小RNA也会经历3'端切割，但不会进行聚腺苷酸化。在这里，我们表明，两个新鉴定的蛋白质Pti1p和Ref2p，尽管它们与前体mRNA 3'端加工复合物相关，但对酵母snoRNA 3'端成熟至关重要。我们还提供了证据表明，Pti1p可能通过解偶联切割和聚腺苷酸化起作用，并与Nrd1p依赖性途径协同作用，参与非聚腺苷酸化转录本的3'端形成。
