Utilizing RNA aptamers to probe a physiologically important heme-regulated cellular network.

Area of Science:

• Molecular Biology
• Synthetic Biology
• Microbiology

Background:

• Modulating intracellular small molecules is crucial for understanding cellular functions.
• RNA aptamers offer a potential strategy for targeted molecular control within cells.

Purpose of the Study:

• To investigate the utility of intracellularly expressed RNA aptamers for modulating heme levels.
• To assess the impact of altered heme concentrations on bacterial growth and metabolism.

Main Methods:

• Development of in vitro selected heme-binding RNA aptamers.
• Intracellular expression of RNA aptamers in Escherichia coli heme auxotrophs.
• Analysis of bacterial growth, delta-aminolevulinic acid (delta-ALA) accumulation, and response to external heme supplementation.

Main Results:

• Intracellular heme-binding RNA aptamers induced a heme-dependent growth defect in E. coli.
• Aptamers led to the accumulation of delta-ALA under heme-limiting conditions.
• Heme supplementation partially or fully reversed the observed growth defect and delta-ALA accumulation.

Conclusions:

• RNA aptamers can specifically target and modulate intracellular heme concentrations in vivo.
• These aptamers serve as effective tools for dissecting the regulatory roles of heme in cellular networks.
• The findings support the broader application of RNA aptamers for studying other small molecules in cellular processes.