CAREER: Nuclear RNA Processing, Coilin and Cajal Bodies

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

How molecular events, such as RNA transcription and maturation, influence nuclear architecture is an important physiological aspect of the eukaryotic cell nucleus. In recent years this central question promoted renewed interest in the organization of the nucleus and rediscovery of several discrete nuclear organelles. The overall objective of this research project is to evaluate the role of one of these nuclear organelles, the Cajal body (CB), in the regulation of nuclear RNA processing. The main experimental system used is the nucleus of Xenopus laevis oocytes, because it provides the unique opportunity to approach this question with unequaled spatial resolution. Two essential questions will be addressed: What is the functional relevance of small nuclear ribonucleoprotein particles (snRNPs) trafficking through CBs, and how does coilin, the signature protein of CBs, recruit snRNPs to CBs? Coilin will be used as a molecular tool to prevent the entry of snRNPs into CBs, without affecting the apparent physiology of the latter. It will allow the investigation in vivo of whether the flow of snRNPs through CBs is required for some aspects of their maturation and/or the processing of pre-messenger RNAs. Biochemical fractionations will also be performed on oocyte extracts to identify the putative nucleoplasmic proteins and RNAs that interact with coilin. This information will then be used in various cell systems to define the molecular mechanisms by which coilin, and the newly identified factors, recruit snRNPs to CBs. Investigation of coilin's biochemistry and cellular dynamics in relation with snRNPs will provide new insights into the nuclear roles of CBs. Because of its visual appeal and accessibility, this research is highly amenable to an active outreach program. It will be applied at several educational levels by mentoring a high school biology teacher and class, and introducing many undergraduate and community college students, including women and minorities, to the wonders of biology and new imaging technologies.