CAREER: Pre-mRNA Splicing and the Coordinated Network of Gene Expression Machineries

生物学中最重要的挑战之一是了解遗传信息是如何表达的，以及这种表达是如何调节的。 人类基因（以及其他真核生物的基因）被一段很长的非编码DNA序列打断。一旦DNA被细胞机器“读取”以制造信使RNA（指导蛋白质合成的中间，包含信息的遗传物质），非编码RNA必须被去除，剩余的蛋白质编码区域连接起来。 这一过程称为“前信使RNA剪接”，精确度极高，对基因的正确表达至关重要。 基因组的另一个显著特征是它的DNA被包装在一个紧凑的蛋白质/DNA结构中，即染色质。 为了使DNA序列被读取用于信使RNA合成，染色质必须经历调节DNA可及性的广泛修饰。 虽然参与基因表达的反应通常被作为独立的、孤立的过程进行研究，但有新的证据表明，RNA合成和剪接实际上是紧密协调的。 RNA合成反应可以影响剪接过程，而前mRNA剪接可以影响RNA合成;然而，这种情况发生的机制仍有待阐明。 使用生物化学和遗传学上易于处理的模式生物，酵母酿酒酵母，这个CAREER项目表征了前mRNA剪接和RNA合成机制的组分之间的相互作用，以及这些相互作用在调节基因表达中所起的作用。 此外，这项工作描述了剪接因子在调节染色质修饰中的意想不到的作用，并探讨了这种活性如何协调RNA合成和前mRNA剪接。这个职业生涯项目的教育部分侧重于（1）本科课程的开发，探索真核基因表达的新兴模式，以及（2）通过与当地高中教师和学生合作，开发基于探究的科学课程，探索基因表达的分子生物学，增加代表性不足的学生的访问和机会。

One of the most important challenges in biology is understanding how genetic information is expressed and how this expression is regulated. Human genes (and the genes from other eukaryotic organisms) are interrupted by long stretches of noncoding DNA sequence. Once the DNA is "read" by the cellular machinery to make messenger RNA (the intermediate, information-containing genetic material that directs protein synthesis), the noncoding RNA must be removed, and the remaining protein-coding regions are joined. This process, "pre-messenger RNA splicing," takes place with exquisite accuracy and is crucial for proper gene expression. Another remarkable feature of the genome is that its DNA is packaged in a compact protein/DNA structure, chromatin. In order for the DNA sequence to be read for messenger RNA synthesis, the chromatin must undergo extensive modification that regulates DNA accessibility. While the reactions involved in gene expression have typically been studied as independent, isolated processes, there is new evidence that RNA synthesis and splicing are, in fact, tightly coordinated. The RNA synthesis reaction can affect the process of splicing, and pre-mRNA splicing can affect RNA synthesis; however, the mechanism by which this occurs remains to be elucidated. Using the biochemically and genetically tractable model organism, the yeast Saccharomyces cerevisiae, this CAREER project characterizes interactions between components of the pre-mRNA splicing and RNA synthesis machineries and the role that these interactions play in modulating gene expression. Additionally, this work describes an unexpected role for splicing factors in modulating chromatin modification and explores how this activity coordinates RNA synthesis and pre-mRNA splicing. The educational component of this CAREER project focuses on (1) development of an undergraduate course to explore emerging models of eukaryotic gene expression and (2) increasing access and opportunities for underrepresented students by working in collaboration with local high school teachers and students developing inquiry-based science curricula exploring the molecular biology of gene expression.