SR PROTEINS AND TRANS SPLICING

这项研究的长期目标是了解SR的作用 线虫中剪接前导（SL）附加反式剪接蛋白 蛔虫。 这是一个反应，增加了一个短外显子，SL， 前mRNA转录物的5'端。 领域的最新发展 在高等真核生物中的前mRNA顺式剪接已经证明SR 蛋白质剪接因子在许多不同的方面起着重要的作用 组成性和调节性剪接。 建立了A. 已经描述了蚯蚓胚胎催化反式和顺式 拼接 这里提出的实验将检查SR的参与 蛋白质的反式剪接，并特别强调比较 它们在顺式剪接反应中的作用。蚯蚓和在 哺乳动物组织培养细胞。 提出了五个具体目标; 1。 到 分离单个A.并克隆其基因。2. 研究A.蛔虫SR蛋白的反式和顺式 体外剪接，并将这些结果与哺乳动物顺式剪接进行比较 反应. 3. 详细研究了A.蛔虫 SR蛋白质与SL RNA/RNP。 4. 为了确定蛋白质-蛋白质 A之间的相互作用蚯蚓SR蛋白以及SR之间 蛋白质和其他细胞因子。 5. 为了确定 A.蚯蚓SR 蛋白质在发育过程中 本申请中提出的实验将允许SR的作用 蛋白质在反式剪接中被确定，因此代表了一种新的 在检查这种RNA加工反应的方向， 广泛分布于低等真核生物中。 这些生物体中的许多在医学上是 对反式剪接反应的重要和完整的剖析可以 提供了一种产生新疗法的途径。

The long term goal of the proposed research is to understand the role of SR proteins in spliced leader (SL) addition trans splicing int he nematode Ascaris lumbricoides. This is a reaction that adds a short exon, the SL to the 5' end of pre-mRNA transcripts. Recent developments in the field of pre-mRNA cis splicing in higher eukaryotes have demonstrated that SR protein splicing factors play an important part in many different aspects of constitutive and regulated splicing. An in vitro system from A. lumbricoides embryos has been described that catalyzes both trans and cis splicing. The experiments proposed here will examine the involvement of SR proteins in trans splicing, and with a particular emphasis on comparisons to their roles in cis-splicing reactions i both A. lumbricoides and in mammalian tissue culture cells. Five specific aims are proposed; 1. To isolate individual A. lumbricoides SR proteins and to clone their genes. 2. To examine the effects of A. lumbricoides SR protein on trans and cis - splicing in vitro and to compare these results to mammalian cis-splicing reactions. 3. To examine in detail the interaction of the A. lumbricoides SR proteins with the SL RNA/RNP. 4. To determine the protein-protein interactions among A. lumbricoides SR proteins as well as among the SR proteins and other cellular factors. 5. To determine the difference in the expression/post-transcriptional modification of the A. lumbricoides SR proteins throughout development. The experiments proposed in this application will allow the role of SR proteins to be determined in trans splicing and therefore represent a new direction in the examination of this RNA processing reaction that is so widespread among lower eukaryotes. Many of these organisms are medically important and a complete dissection of the trans-splicing reaction may provide a route to the generation of novel therapeutics.