Researchers at the Friedrich Schiller University Jena have discovered a dual function of a regulatory RNA in Vibrio cholerae, the causative agent of Cholera, that couples the production of its toxin with its ability to metabolise carbon. RNA is a molecule closely related to DNA that can possess genetic coding as well as regulatory functions governing the expression of genes that mediate all cellular functions.

Prof. Papenfort and his team at the Institute of Microbiology discovered that one such small RNA called VcdRP is not simply a non-coding regulator but also contains a small open reading frame that produces a regulatory protein. The investigators showed that as an RNA VcdRP is a repressor of Cholera toxin production by inhibiting carbon transport. In addition, the small protein VcdP that is encoded by VcdRP directly activates a component of the citric acid cycle, a central pathway that converts dietary carbon into biosynthetic building blocks.

“Our work demonstrates that the production of toxin, and hence the disease-causing properties of the Cholera bacterium, is directly coupled to the bacterial metabolism via the same RNA molecule”, says Papenfort. This can open up new avenues of combating the disease but also has implications for biotechnological applications using microorganisms that exploit the same mechanism.

Press release by Ute Schönfelder (FSU Jena)

Original publication

Venkat K, Hoyos M, Haycocks J, Cassidy L, Engelmann B, Rolle-Kampczyk U, von Bergen M, Tholey A, Grainger DC, Papenfort K (2021) A dual-function RNA balancing carbon uptake and central metabolism in Vibrio cholerae. EMBO Journal, e108542, https://doi.org/10.15252/embj.2021108542.