Some fungi can emit light. This glow, called bioluminescence, has been widely studied, but the biology underlying this light emission remains incompletely understood.
Bioluminescence is extensively used in scientific research, and enables real-time imaging of dynamic processes like tumour progression or inflammatory responses, making it a valuable tool in medicine. Therefore, understanding the exact mechanisms that make fungi glow could provide important insights into improving and expanding bioluminescence-based tools and applications.
In bioluminescent fungi, light is produced in the final stage of a step-wise reaction called the ‘fungal bioluminescence pathway’, and a byproduct of this light-producing reaction is oxyluciferin. In order to keep this pathway going, oxyluciferin needs to be broken down, with the resulting products then recycled back into the pathway, thus also preventing substrate depletion. Previous studies have suggested a role for an enzyme, caffeylpyruvate hydrolase (CPH), in breaking down oxyluciferin, but the results are inconclusive. Two recent papers published in The FEBS Journal sought to clarify this.
Caio Zamuner and co-investigators characterised CPH from one of the largest and brightest bioluminescent fungal species described to date, confirming that it could indeed break down oxyluciferin, thus enabling recycling of the products of this reaction back into the bioluminescence pathway [1]. The authors also developed a new method to monitor CPH activity, thus providing a useful resource for further studies on bioluminescence.
In their companion study, Alena Malyshevskaia and co-authors dove deeper into the ‘upstream’ oxyluciferin-CPH relationship in the bioluminescence pathway, and showed that oxyluciferin can accumulate post-light production and act as an inhibitor of luciferase, the ‘light-producing’ enzyme, thus interrupting the pathway’s continuity [2]. They propose that the cph gene evolved to alleviate this build-up of oxyluciferin, therefore allowing the continuous cycling of the pathway and consequently, light production to occur.
Collectively, these studies confirm a role for CPH in making fungi glow, and illuminate new opportunities for engineering self-sustained light-emitting systems in other organisms, biological sensors to monitor ecosystems and track pollution, and eco-friendly lighting.
Who knows? One day, instead of reaching for the light switch on a lamp, or grabbing a glow stick or two before going to a concert, we might find ourselves accompanied by a friendly fungus who never leaves us alone in the dark.
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References:
[1] Zamuner, C.K., Soares, D.M.M., Nóbrega, B.B., Bechara, E.J.H., Kaskova, Z.M., Mishin, A.S., Sarkisyan, K.S., Yampolsky, I.V. and Stevani, C.V. (2026), Caffeylpyruvate hydrolase from the bioluminescent fungus Neonothopanus gardneri is the key recycling enzyme in the fungal bioluminescence pathway. FEBS J. https://doi.org/10.1111/febs.70554
[2] Malyshevskaia, A.K., Barykin, A.D., Kisilichuk, D.A., Chepurnykh, T.V., Shakhova, E.S., Perfilov, M.M., Belozerova, O.A., Palkina, K.A., Markina, N.M., Zamuner, C.K., Soares, D.M.M., Zagitova, R.I., Kaskova, Z.M., Stevani, C.V., Gorokhovatsky, A.Y., Mishin, A.S., Sarkisyan, K.S. and Yampolsky, I.V. (2026), Fungal oxyluciferin is recycled by caffeylpyruvate hydrolases. FEBS J. https://doi.org/10.1111/febs.70555
Cover image courtesy of Teresa Sarria.