In a multidisciplinary study recently published in Nature Chemical Biology, researchers at the University of Colorado Boulder have developed a novel tool for visualizing RNA. This project centered on a collaboration between the Palmer Lab, with expertise in live cell imaging, the Batey Lab, with expertise in RNA, and the Gryko Lab with expertise in chemical synthesis. Researchers from the Parker and Jimenez labs also contributed to the study.
RNA, or ribonucleic acid, is a macromolecule essential to all forms of life. RNA plays a key role in gene expression and regulation, catalyzes the formation of polypeptides, and facilitates the transformation of genetic information from DNA to protein. Considering the many functions of this diverse molecule, visualizing RNA is essential to understanding a wide array of cellular processes.
Visualization of U-bodies in live mammalian cells
“As the community continues to discover new functions for coding and non-coding RNAs, the desire to look at them over time in live cells can provide unique functional insights“, commented Esther Braselmann, the lead author on this study and member of the Palmer Lab at the BioFrontiers Institute. Dr. Braselmann recently won a prestigious NIH K99 award, which helps outstanding postdoctoral researchers transition to tenure-track positions.
Established techniques to fluorescently tag and track RNA have several limitations. These tags are not compatible with all types of RNA, perform poorly in live cell studies, and can interfere with normal RNA activity due to their large size. The authors of this study sought to create a versatile imaging platform applicable to real-time experiments in live cells.
The methodology presented in this study relies on a Cobalamin-fluorophore probe which fluoresces upon binding to riboswitch RNA. This system is highly adaptable, allowing researchers to target diverse types of RNA and customize the probe with fluorophores of different colors.
The authors employed this Riboglow technology to visualize mRNA dynamics in live mammalian cells. They were able to record mRNA localization to stress granules, and visualize U1 snRNA in live cells for the first time. When compared to other imaging techniques, Riboglow was less susceptible to photobleaching and demonstrated a robust fluorescent signal.
“We view Riboglow as a complementary platform to existing tools and an addition to the growing toolbox for labeling RNAs,” remarked Dr. Braselmann. The versatility of the Riboglow platform will allow for widespread application to continue illuminating the many roles of RNA in live cells.
This research was supported by the Human Frontiers Science Project, the National Institute of Health, and the National Science Centre.