Next-generation RNA synthesis and labeling kits - SUMMARY: Circular RNAs are an important class of RNAs that have fundamental cellular functions and
have the potential to be novel types of RNA-based therapeutics. Circular RNAs are difficult to synthesize
and purify due to low yields after gel extraction. Resolving these issues could be a major benefit to
academic and biotechnology research on circular RNA. The goal of this proposal is to make RNA synthesis
as simple as a DNA plasmid prep kit. To do this, we will develop two new high-impact, market-ready kits.
Our first kit is the “Chimerna In-cell circular RNA purification kit,” which uses our “Tornado” technology
for expressing RNAs as a circle. When used in E. coli, the Tornado technology results in the production of
RNA at high levels not previously seen with conventional linear RNAs. The stability of circular RNA allows it
to accumulate to high levels in E. coli, and also confers high stability in vitro and when transfected into
mammalian cells, thus mitigating the persistent degradation problem of conventional linear RNAs. We also
developed a new RNA-purification aptamer which we incorporate into our circles to achieve high purity with
a simple one-step elution protocol. Thus, our kit will overcome the problems of in vitro transcription: low
yield, complex enzymatic synthesis reaction, RNA degradation, and the problem of laborious RNA
purification. We will also prepare the Chimerna RNA labeling kit that repurposes a tRNA-modifying
enzyme for RNA labeling. This companion product, comprising the enzyme and suitable substrates, will
markedly enhance the ability to impart biotin, fluorescent dyes, cell-targeting moieties, and other useful tags
to RNA. In order to develop these new commercial products, our specific aims are: (1) To optimize a kit for
high-yield circular RNA synthesis and purification without in vitro transcription. We will optimize the E. coli
cell line, culturing conditions, dextran binding and elution conditions, and RNA storage conditions. We will
also establish protocols, manuals, reproducibility and stability conditions for kitting; (2) To develop an
approach for simple and efficient RNA labeling. We will optimize reaction labeling conditions and target
RNA sequences, develop protocols, manuals, and establish stability conditions that will allow us to create a
user-ready RNA labeling kit; (3) To develop a system for highly efficient elution of tag-free RNA circles from
dextran beads. We will perform pilot experiments to test a completely new RNA purification kit involving on-
bead RNA circularization and elution triggered by a small molecule. This system is highly simplified and
fast, with even fewer contaminants and produces RNA without any affinity tags. Taken together, this project
will result in the first kit for synthesizing circular RNA, an especially challenging but highly important type of
RNA. This technology is extended with our innovative RNA labeling kit, enabling researchers to label, tag,
or track RNAs for diverse applications. These new kits will markedly accelerate circular RNA research.