Graveley B R, Maniatis T
Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
Mol Cell. 1998 Apr;1(5):765-71. doi: 10.1016/s1097-2765(00)80076-3.
Serine/arginine (SR)-rich splicing factors contain an RNA binding domain and an arginine/serine (RS)-rich domain required for protein-protein interactions. In addition to their roles in the basic splicing reaction, SR proteins function as components of splicing enhancer complexes. Here, we investigate the role of RS domains in splicing enhancer function. Hybrid proteins containing RS domains fused to the MS2 RNA binding protein were tested in vitro with RNA substrates bearing an MS2 recognition sequence. These hybrid proteins activated splicing in nuclear extracts, but not in S100 extracts lacking SR proteins. However, intact recombinant SR proteins could complement the activity of the hybrid proteins in S100 extracts. These data demonstrate that RS domains function as splicing activators and suggest that the general and enhancer-dependent functions of SR proteins can be uncoupled.
富含丝氨酸/精氨酸（SR）的剪接因子包含一个RNA结合结构域和一个蛋白质-蛋白质相互作用所需的富含精氨酸/丝氨酸（RS）的结构域。除了在基本剪接反应中的作用外，SR蛋白还作为剪接增强子复合物的组成部分发挥作用。在这里，我们研究RS结构域在剪接增强子功能中的作用。将含有与MS2 RNA结合蛋白融合的RS结构域的杂合蛋白与带有MS2识别序列的RNA底物进行体外测试。这些杂合蛋白在核提取物中激活剪接，但在缺乏SR蛋白的S100提取物中则不能。然而，完整的重组SR蛋白可以补充S100提取物中杂合蛋白的活性。这些数据表明RS结构域作为剪接激活剂发挥作用，并表明SR蛋白的一般功能和增强子依赖性功能可以分离。
