The correct folding of structured RNA molecules is essential for a multitude of biological processes, but RNAs are prone to misfold, typically leading to disease. RNA-binding chaperone proteins, including CYT-19 of the DEAD-box family, have evolved to assist the proper folding of RNA molecules. Previous work using CYT-19 and a non-physiological group I RNA has provided great insight into how chaperone proteins work, but extensive research using cognate RNA and protein have not been performed. This current work will investigate the interaction between CYT-19 and the group I intron ND1, both from the mitochondria of Neurospora crassa. ND1 requires the binding of a protein cofactor, CYT-18, to properly fold and become catalytically active, and is capable of misfolding and slowly transitioning to a correctly-folded native state. The overall goal of this work is to enhance understanding of RNA folding and RNA-protein interactions as can be applied to preventing diseases based on misfolded RNAs. The first specific aim of this research is to characterize the misfolded state of ND1 by determining if the RNA populates one or more misfolded configurations, the extent of unfolding during the transition, and, if possible, the structure of the misfolded RNA.
The second aim i s to determine if CYT-19 accelerates refolding of ND1 from misfolded to native states, testing whether CYT-19 must displace CYT-18 in order to act on the RNA. The last aim is to determine if CYT-19 unfolds correctly-folded ND1 and, if so, compare its ability to unfold a cognate RNA with its previously determined ability to unfold a non-physiological RNA. Understanding RNA folding and the consequences of incorrect folding on biology provide insight into how diseases caused by improper folding, including many forms of cancer, may be treated or cured. Furthermore, ensuring the proper and stable folding of RNAs, such as small interfering RNAs designed to block gene expression, will enhance the effectiveness of such medical treatments.
|Mitchell 3rd, David; Russell, Rick (2014) Folding pathways of the Tetrahymena ribozyme. J Mol Biol 426:2300-12
|Mitchell 3rd, David; Jarmoskaite, Inga; Seval, Nikhil et al. (2013) The long-range P3 helix of the Tetrahymena ribozyme is disrupted during folding between the native and misfolded conformations. J Mol Biol 425:2670-86