Newo Alain N S, Lützelberger Martin, Bottner Claudia A, Wehland Jürgen, Wissing Josef, Jänsch Lothar, Käufer Norbert F
Institute of Genetics, Technical University of Braunschweig, Spielmannstr. 7, 38106 Braunschweig, Germany.
Nucleic Acids Res. 2007;35(5):1391-401. doi: 10.1093/nar/gkl1144. Epub 2007 Jan 30.
Characterization of spliceosomal complexes in the fission yeast Schizosaccharomyces pombe revealed particles sedimenting in the range of 30-60S, exclusively containing U1 snRNA. Here, we report the tandem affinity purification (TAP) of U1-specific protein complexes. The components of the complexes were identified using (LC-MS/MS) mass spectrometry. The fission yeast U1 snRNP contains 16 proteins, including the 7 Sm snRNP core proteins. In both fission and budding yeast, the U1 snRNP contains 9 and 10 U1 specific proteins, respectively, whereas the U1 particle found in mammalian cells contains only 3. Among the U1-specific proteins in S. pombe, three are homolog to the mammalian and six to the budding yeast Saccharomyces cerevisiae U1-specific proteins, whereas three, called U1H, U1J and U1L, are proteins specific to S. pombe. Furthermore, we demonstrate that the homolog of U1-70K and the three proteins specific to S. pombe are essential for growth. We will discuss the differences between the U1 snRNPs with respect to the organism-specific proteins found in the two yeasts and the resulting effect it has on pre-mRNA splicing.
裂殖酵母粟酒裂殖酵母中剪接体复合物的表征揭示了沉降系数在30 - 60S范围内的颗粒，其仅含有U1 snRNA。在此，我们报道了U1特异性蛋白复合物的串联亲和纯化（TAP）。使用（LC-MS/MS）质谱法鉴定了复合物的组分。裂殖酵母U1 snRNP包含16种蛋白质，包括7种Sm snRNP核心蛋白。在裂殖酵母和芽殖酵母中，U1 snRNP分别包含9种和10种U1特异性蛋白质，而在哺乳动物细胞中发现的U1颗粒仅包含3种。在粟酒裂殖酵母的U1特异性蛋白质中，三种与哺乳动物的同源，六种与芽殖酵母酿酒酵母的U1特异性蛋白质同源，而三种名为U1H、U1J和U1L的蛋白质是粟酒裂殖酵母特有的。此外，我们证明U1 - 70K的同源物和粟酒裂殖酵母特有的三种蛋白质对生长至关重要。我们将讨论两种酵母中发现的U1 snRNP在物种特异性蛋白质方面的差异以及它对前体mRNA剪接的影响。
