Legrain P, Chapon C, Galisson F
Département de Biologie Moléculaire, Institut Pasteur, Paris, France.
Genes Dev. 1993 Jul;7(7B):1390-9. doi: 10.1101/gad.7.7b.1390.
The PRP9 protein is a yeast splicing factor implicated in the early steps of spliceosome assembly whose sequence contains an amino-terminal putative leucine zipper structure and two carboxy-terminal motifs reminiscent of zinc fingers. Here, we show that the deletion of the second carboxy-terminal motif results in a dominant lethal phenotype. This observation, combined with an in vivo-binding assay for protein-protein interactions, reveals the presence of two distinct binding sites on the PRP9 protein. The carboxy-terminal region contributes to the PRP9 homodimerization, whereas the amino-terminal region binds the SPP91 splicing factor. Further experiments suggest that other factors bind to PRP9 and SPP91 proteins. Finally, we demonstrate that the PRP9 protein acts after the formation of the U1 snRNP-pre-mRNA complex. The existence of a protein complex including the PRP9 factor is discussed.
PRP9蛋白是一种酵母剪接因子，参与剪接体组装的早期步骤，其序列包含一个氨基末端假定的亮氨酸拉链结构和两个羧基末端类似锌指的基序。在此，我们表明删除第二个羧基末端基序会导致显性致死表型。这一观察结果，结合用于蛋白质-蛋白质相互作用的体内结合试验，揭示了PRP9蛋白上存在两个不同的结合位点。羧基末端区域有助于PRP9同源二聚化，而氨基末端区域结合SPP91剪接因子。进一步的实验表明，其他因子与PRP9和SPP91蛋白结合。最后，我们证明PRP9蛋白在U1 snRNP-前体mRNA复合物形成后起作用。讨论了包含PRP9因子的蛋白质复合物的存在。
