SR PROTEINS AND TRANS SPLICING

拟议研究的长期目标是了解SR的作用 线虫间剪接前导(SL)附加反式剪接中的蛋白质 蛔虫。这是一个添加了短外显子的反应，SL 前信使核糖核酸转录产物的5‘端。……领域的最新发展 高等真核生物中的前mRNA顺式剪接已证明SR 蛋白质剪接因子在许多不同的方面发挥着重要作用 构成的和规范的剪接。本研究建立了A. 蚯蚓胚胎已被描述为同时催化反式和顺式。 拼接。这里提出的实验将检验SR的参与 反式剪接中的蛋白质，并特别强调比较 它们在顺式剪接反应中的作用 哺乳动物组织培养细胞。提出五个具体目标：1. 分离蚯蚓单株SR蛋白并克隆其基因。2. 目的：研究蚯蚓SR蛋白对反式和顺式作用的影响。 体外剪接并将这些结果与哺乳动物的顺式剪接进行比较 反应。3.详细研究粘虫之间的相互作用 SR蛋白与SL RNA/RNP的融合。4.蛋白质-蛋白质的测定 蚯蚓SR蛋白之间以及SR之间的相互作用 蛋白质和其他细胞因子。5.确定 粘虫SR基因的表达/转录后修饰 蛋白质在整个发育过程中。 本申请中提出的实验将允许SR的角色 在反式剪接中需要确定的蛋白质，因此代表着一种新的 检查这种RNA加工反应的方向，即 广泛存在于低等真核生物中。这些生物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能 为新疗法的产生提供了一条途径。

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.