Abovich N, Rosbash M
Howard Hughes Medical Institute, Department of Biology, Brandeis University, Waltham, Massachusetts 02254, USA.
Cell. 1997 May 2;89(3):403-12. doi: 10.1016/s0092-8674(00)80221-4.
The commitment complex is the first defined step in the yeast (S. cerevisiae) splicing pathway. It contains U1 snRNP as well as Mud2p, which resembles human U2AF65. In a genetic screen, we identified the yeast gene MSL-5, which is a novel commitment complex component. Genetic and biochemical criteria indicate a direct interaction between Msl5p and both Mud2p and the U1 snRNP protein Prp40p. This defines a bridge between the two ends of the intron. Msl5p (renamed BBP for branchpoint bridging protein) has a mammalian ortholog, the splicing factor SF1. Our results show that SF1 interacts strongly with human U2AF65, and that SF1 is a bona fide E complex component. This implies that aspects of these novel cross-intron protein-protein interactions are conserved between yeast and mammals.
剪接前体复合物是酵母（酿酒酵母）剪接途径中首个被明确的步骤。它包含U1 snRNP以及与人类U2AF65相似的Mud2p。在一次遗传筛选中，我们鉴定出酵母基因MSL-5，它是剪接前体复合物的一个新组分。遗传学和生物化学标准表明Msl5p与Mud2p和U1 snRNP蛋白Prp40p之间存在直接相互作用。这定义了内含子两端之间的一座桥梁。Msl5p（重新命名为分支点桥接蛋白BBP）有一个哺乳动物直系同源物，即剪接因子SF1。我们的结果表明SF1与人U2AF65强烈相互作用，并且SF1是真正的E复合物组分。这意味着这些新型跨内含子蛋白质 - 蛋白质相互作用的某些方面在酵母和哺乳动物之间是保守的。
