The synthesis of Broccoli RNA fluorescent aptamer in Saccharomyces cerevisiae yeast cells

BACKGROUND: RNA aptamers are short, single-stranded oligonucleotides, with remarkable binding ability to target molecules characterized by high specificity and affinity. Such targets are vastly diverse and range from specific ions to entire cells. RNA aptamers are widely used in biology and medicine for basic research, as well as for practical purposes as in therapy and diagnostics. At present, chemical or in vitro methods of synthesis are mainly used to obtain RNA aptamers. However, such methods are expensive and time-consuming with low productivity. Therefore, in vivo methods are becoming more attractive to researchers working on optimizing high-scale production of RNA aptamers. 
AIM: The aim of this work is to develop a reporter system for optimizing the synthesis of small RNA molecules in Saccharomyces cerevisiae yeast cells. 
MATERIALS AND METHODS: We used the Broccoli fluorescent RNA aptamer to develop a reporter system allowing us to optimize the conditions for in vivo short RNA synthesis in yeast cells. This aptamer is about 112 bp in size and binds to the fluorogenic dye DFHBI-1T. Only upon binding, the aptamer-dye complex exhibits fluorescence properties. After excitation using light with a wavelength of 482 nm, the aptamer-dye complex emission is observed with a peak at 505 nm. 
RESULTS: We have designed a reporter system providing the synthesis of the fluorescent Broccoli RNA aptamer in S. cerevisiae yeast cells. Transcription of RNA molecules containing the aptamer is carried out by the regulated promoter of the GAL1 gene. The synthesized transcripts contain the HH and HDV ribozymes to ensure precise cleavage of the RNA aptamer sequences. 
CONCLUSIONS: This reporter system is based on the Broccoli RNA aptamer, and it can be used to optimize the in vivo synthesis of RNA aptamers in S. cerevisiae yeast cells. This work serves an urgent task in connection with the active use of such aptamers in scientific research, biotechnology and medicine.