S‐Adenosyl‐l‐Methionine Salvage Impacts Psilocybin Formation in “Magic” Mushrooms

Psilocybe cubensis mushrooms produce psilocybin through a five-step pathway that consumes ATP and SAM, requiring efficient recycling of these co-substrates. The adenosine kinase and SAH hydrolase enzymes from the fungus help regenerate SAM. Gene expression increases in fungal primordia and fruiting bodies. A one-pot reaction combining the methyltransferase PsiM with SAH hydrolase shows that removing the byproduct SAH enables continued biosynthesis.

Study at a glance

Abstract

Abstract Psychotropic Psilocybe mushrooms biosynthesize their principal natural product psilocybin in five steps, among them a phosphotransfer and two methyltransfer reactions, which consume one equivalent of 5′‐adenosine triphosphate (ATP) and two equivalents of S ‐adenosyl‐ l ‐methionine (SAM). This short but co‐substrate‐intensive pathway requires nucleoside cofactor salvage to maintain high psilocybin production rates. We characterized the adenosine kinase (AdoK) and S ‐adenosyl‐ l ‐homocysteine (SAH) hydrolase (SahH) of Psilocybe cubensis . Both enzymes are directly or indirectly involved in regenerating SAM. qRT‐PCR expression analysis revealed an induced expression of the genes in the fungal primordia and carpophores. A one‐pot in vitro reaction with the N ‐methyltransferase PsiM of the psilocybin pathway demonstrates a concerted action with SahH to facilitate biosynthesis by removal of accumulating SAH.