PHOSPHORYLATION AND THE REGULATION OF RNA SPLICING

前体基因选择性剪接对基因表达的影响 产品涉及多个方面的细胞生长和 分化，然而它的调节机制是 只是刚刚开始被阐明。SR蛋白及其相关因素 都被认为在调节 拼接。这些因素在现场形成了调控复合体。 在选择性剪接的前mRNAs的外显子内部和 从通用拼接机械中汲取因素的功能 到附近的剪接部位，否则就不会被识别。 尽管SR蛋白高度磷酸化，但它的作用是 磷酸化在剪接调控中的作用在很大程度上是未知的。 我们建议研究SR蛋白的磷酸化如何影响 性别特异性调控复合体的组装和功能 形成于双性前信使核糖核酸的剪接增强子。 初步研究表明，Lammer Kinase Darkener-of- 杏树使SR蛋白磷酸化，是正常发育所必需的 双性性别RNA剪接的调控。我们将测试是否 双性剪接增强子中蛋白质的磷酸化 复合体影响SR蛋白的能力，并与之相关 调控因子，如TRA和TRA2，相互作用 其他和与前信使核糖核酸。其他实验将比较 不同类型的激酶对SR蛋白功能的影响。 最后，我们将培育出基因突变的果蝇。 SR蛋白激酶研究它们在发育和其他方面的作用 体内特定SR蛋白的磷酸化。我们 预计这些研究将提供重要的新的 对剪接调控和剪接机制的洞察 将为未来磷酸化的研究开辟新的途径 SR蛋白。

Alternative pre-mRNA splicing affects the expression of gene products involved in many aspects of cell growth and differentiation, yet the mechanisms by which it is regulated are only beginning to be elucidated. SR proteins and related factors are thought to play important roles in the regulation of splicing. These factors form regulatory complexes at sites internal to the exons of alternatively spliced pre-mRNAs and function to recruit factors from the general splicing machinery to nearby splice sites that otherwise would not be recognized. Although SR proteins are highly phosphorylated, the role of phosphorylation in the regulation of splicing is largely unknown. We propose to investigate how SR protein phosphorylation affects the assembly and function of sex-specific regulatory complexes formed on a splicing enhancer in the doublesex pre-mRNA. Preliminary studies indicate that the LAMMER kinase Darkener-of- apricot phosphorylates SR proteins and is required for normal regulation of doublesex RNA splicing. We will test whether the phosphorylation of proteins from the doublesex splicing enhancer complex affects the ability of SR proteins, and related regulatory factors such as TRA and TRA2, to interact with each other and with the pre-mRNA. Other experiments will compare the effects of different classes of kinases on SR protein function. Finally, we will produce strains of Drosophila with mutations in SR protein kinases to examine their roles in development and on the phosphorylation of specific SR proteins in vivo. We anticipate that these studies will provide significant new insights into the mechanisms by which splicing is regulated and will open up new avenues for future studies on phosphorylation of SR proteins.