Regulation of alternative splicing by SRrp86 and its interacting proteins
Regulation of alternative splicing by SRrp86 and its interacting proteins
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DOI：
10.1128/mcb.23.21.7437-7447.2003
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发表时间：
2003-11-01
影响因子：
5.3
通讯作者：
Patton, JG
中科院分区：
文献类型：
--
作者：
Li, J;Hawkins, IC;Patton, JG
SRrp86 是 SR 蛋白超家族的独特成员，包含一个 RNA 识别基序和两个富含丝氨酸-精氨酸 (SR) 的结构域，并由一个不寻常的富含谷氨酸-赖氨酸 (EK) 的区域分隔开。此前，我们证明SRrp86可以通过正向和负向调节其他SR蛋白的活性来调节选择性剪接，并且独特的EK结构域可以抑制组成型剪接和选择性剪接。这些功能与 SRrp86 通过与靶蛋白相互作用并从而调节其活性而发挥作用的模型最为一致。为了鉴定与 SRrp86 相互作用的特定蛋白质，我们使用了酵母双杂交文库筛选和免疫沉淀与质谱联用。我们发现 SRrp86 与所有核心 SR 蛋白以及其他剪接调节蛋白的子集相互作用，包括 SAF-B、hnRNP G、YB-1 和 p72。与之前显示 SRrp86 激活 SRp20 的结果相反，我们现在表明 SAF-B、hnRNP G 和 9G8 均拮抗 SRrp86 的活性。总的来说，我们得出的结论是，SRrp86 不仅调节 SR 蛋白活性，而且反过来又受到其他剪接因子的调节，以控制选择性剪接位点选择。
SRrp86 is a unique member of the SR protein superfamily containing one RNA recognition motif and two serine-arginine (SR)-rich domains separated by an unusual glutamic acid-lysine (EK)-rich region. Previously, we showed that SRrp86 could regulate alternative splicing by both positively and negatively modulating the activity of other SR proteins and that the unique EK domain could inhibit both constitutive and alternative splicing. These functions were most consistent with the model in which SRrp86 functions by interacting with and thereby modulating the activity of target proteins. To identify the specific proteins that interact with SRrp86, we used a yeast two-hybrid library screen and immunoprecipitation coupled to mass spectrometry. We show that SRrp86 interacts with all of the core SR proteins, as well as a subset of other splicing regulatory proteins, including SAF-B, hnRNP G, YB-1, and p72. In contrast to previous results that showed activation of SRp20 by SRrp86, we now show that SAF-B, hnRNP G, and 9G8 all antagonize the activity of SRrp86. Overall, we conclude that not only does SRrp86 regulate SR protein activity but that it is, in turn, regulated by other splicing factors to control alternative splice site selection.