Eckert Daniela, Andrée Nicole, Razanau Aleh, Zock-Emmenthal Susanne, Lützelberger Martin, Plath Susann, Schmidt Henning, Guerra-Moreno Angel, Cozzuto Luca, Ayté José, Käufer Norbert F
Institute of Genetics, Technische Universität Braunschweig, Braunschweig, Germany.
Department of Physiology and Pathophysiology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada.
PLoS Genet. 2016 Jan 5;12(1):e1005768. doi: 10.1371/journal.pgen.1005768. eCollection 2016 Jan.
The genome of the fission yeast Schizosaccharomyces pombe encodes 17 kinases that are essential for cell growth. These include the cell-cycle regulator Cdc2, as well as several kinases that coordinate cell growth, polarity, and morphogenesis during the cell cycle. In this study, we further characterized another of these essential kinases, Prp4, and showed that the splicing of many introns is dependent on Prp4 kinase activity. For detailed characterization, we chose the genes res1 and ppk8, each of which contains one intron of typical size and position. Splicing of the res1 intron was dependent on Prp4 kinase activity, whereas splicing of the ppk8 intron was not. Extensive mutational analyses of the 5' splice site of both genes revealed that proper transient interaction with the 5' end of snRNA U1 governs the dependence of splicing on Prp4 kinase activity. Proper transient interaction between the branch sequence and snRNA U2 was also important. Therefore, the Prp4 kinase is required for recognition and efficient splicing of introns displaying weak exon1/5' splice sites and weak branch sequences.
裂殖酵母粟酒裂殖酵母的基因组编码17种对细胞生长至关重要的激酶。这些激酶包括细胞周期调节因子Cdc2，以及几种在细胞周期中协调细胞生长、极性和形态发生的激酶。在本研究中，我们进一步对这些必需激酶中的另一种Prp4进行了表征，并表明许多内含子的剪接依赖于Prp4激酶活性。为了进行详细表征，我们选择了res1和ppk8基因，每个基因都包含一个典型大小和位置的内含子。res1内含子的剪接依赖于Prp4激酶活性，而ppk8内含子的剪接则不依赖。对这两个基因5'剪接位点的广泛突变分析表明，与snRNA U1的5'末端进行适当的瞬时相互作用决定了剪接对Prp4激酶活性的依赖性。分支序列与snRNA U2之间的适当瞬时相互作用也很重要。因此，Prp4激酶是识别和有效剪接显示弱外显子1/5'剪接位点和弱分支序列的内含子所必需的。
